WA P246e 1895




63030210R
NLH 05130601  1
NATIONAL LIBRARY OF MEDICINE
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*  SURGEON GENERAL'S OFFK'E
LIBRARY
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THE ELEMENTS OF HEALTH 
 
THE
ELEMENTS OF  HEALTH

 AN INTRODUCTION TO THE STUDY
         OF HYGIENE
          (  BY

 LOUIS C. PARKES, M.D., D.P.H.Lond.
3DICAL OFFICER OF HEALTH FpR CHELSEA; LECTURER ON PUBLIC HEALTH AT
9T. GEORGE S HOSPITAL
ILLUSTRATIONS BY HENRY PARKES, A.M., INST.C.E.
*Mm
!^k^   :
    PHILADEL/PHIA
P. BLAKISTON, SON & CO.
    1012, WALNUT STREET
         1895 
 
PREFACE
  The intention of this  little  work—as its title
explains—is to form an introduction to the  study
of Hygiene.  The author's main idea has been to
give some simple yet practical information and
instruction  on the preservation of individual  or
personal health in the ordinary  routine of domestic
life.  An attempt has been made  to place within
the small compass of the following pages just that
amount of practical knowledge in  Hygiene which
it is desirable that every individual should be in
possession of.   Matters relating to questions  of
Public Health—over which the individual citizen
has little or no control—have for the most part been
avoided.
                                      L. C. P.
  61, Cadogan Sqtjabe, S.W.
       April, 1895. 
 
CONTENTS
CHAPTER  I

    WATER
Sources of Supply
Rain-water
Streams and Rivers .
Wells
Springs
Public Water Supplies
Constant and Intermittent Supply
Cisterns
Purification of Water
Domestic Filters
Sand Filtration
 CHAPTER II
DOMESTIC REFUSE
Ashpits and Dustbins
Privies, Middens, and Cesspools
Pail, Ash, and Earth Closets
Water-closets
Soil-pipes 
Vlll
CONTENTS
House Drains
Testing Drains
Waste-pipes  ....
Gullies and Bell-traps
The Flushing and Cleansing of Drains
PAGE
  55
  58
  60
  67
  71
                    CHAPTER III

                AIR AND VENTILATION

Composition of Air  ....
Fouling of the Air by Respiration .
    „    „    „     Combustion .
    „    „    „     Rotting Organic Refuse
Ventilation  .....
Cubic Space and Floor Space
Introduction of Fresh Air into Rooms
Exhaustion of  Fouled Air  .
Practical Examination of the Ventilation of  Rooms
Measurement of Cubic and Floor Space
 77
 81
 86
 93
 99
 99
104
112
117
118
CHAPTER IV	
WARMING	
Open Fireplaces ....	. 121
Coal and Pollution of the Air by Smoke	. 122
Gas Fires .....	. 127
Ventilating Fireplaces	. 129
Ventilating and Close Stoves	. 132
Hot-water Pipes ....	. 134
 
CONTENTS
ix
	CHAPTER V	
	LIGHTING	PAGE
Daylight Illuminatioi	i of Rooms	. 135
Artificial Lighting		. 137
Electric Light		. 138
Gas .		. 138
Lamps		. 139
Candles		. 139
                 CHAPTER  VI
HOUSE CONSTRUCTION IN ITS SANITARY ASPECT
Damp Houses and Disease
Subsoil Air and Subsoil Water
Pollution of the Subsoil
Prevention of  Dampness in Houses .
Ventilation under Floors
Bad Design in the Planning of Houses
Household Dust
Floors, Walls, and Ceilings .
140
141
142
146
149
152
154
156
        CHAPTER VII
SITE  AND SITUATION OF HOUSE
Varieties of Soil
Exposure of Site
Elevation
Bracing and Relaxing Localities
Influence of Vegetation and Water
159
161
162
162
163 
X
CONTENTS
CHAPTER  VIII
       FOOD
Classification of Foods
Composition of Foods
Animal and Vegetable Diets
Digestibility of Various Foods
Cooking
Variety and Admixture
Meal-times
Appetite:  Mastication of Food
Excessive Meals
The Digestive Process
Soups, Broths, and Jellies   .
Meat, Fish, Tinned Foods   .
Oysters
Milk  ....
Mother's Milk and Cow's Milk
Suckling and Hand-feeding
Infants' Foods
Sterilisation of Milk
Storage of Milk
Butter and Cheese   .
Bread
Farinaceous Foods
Fresh Vegetables and Fruits
Condiments  .
Alcoholic Beverages .
Malt Liquors
Wines
Spirits      .      .
Tea, Coffee, and Cocoa
Mineral Waters 
CONTENTS
XI
  CHAPTER IX
PHYSICAL EXERCISE
Effects of Exercise on the Bodily Or
Rest .
Growth of the Body  .
Kinds of Exercise—
    Walking
    Running
    Jumping
    Rowing .
    Games  .
    Feats of Strength
Training or Preparation
                    CHAPTER  X
                       CLOTHING
Use of Clothing
Amount and Character of Clothing .
Underclothing and Chills
Outdoor Clothes
Wet Feet, Damp Beds, and " Draughts "
Constricting Garments—
    Hats, Belts,  Stays, Garters, and Boots
Clothing in Childhood and in Old Age
Cleanliness of Clothing
                    CHAPTER XI
   THE CARE OF  THE SKIN,  TEETH, AND BOWELS
The Skin as an Excretory Organ
Soaps and Ablution .
Hot and Cold Bathing
Attention to the Teeth
Importance of Regular Action of the Bowels 
 
CHAPTER I
                     WATER
Sources of  supply—Rain-water—Streams and rivers—Wells—
    Springs—Public  water-supplies—Constant and intermittent
    supply: Cisterns—Purification  of water: Domestic filters,
    Sand filtration.
  Sources   of Supply.—Our  water-supplies  are
derived from the rain which falls upon the ground.
Upon reaching the surface  of  the  earth, the rain
is disposed of in one  of three ways, namely, (1)
by  evaporation, (2) by flowing  off the surface, (3)
by percolation, or sinking into the soil.
  By evaporation is meant that the water is con-
verted into invisible vapour, which is absorbed into
the atmosphere.    Evaporation is always greatest
when the temperature of the air is highest.   Conse-
quently it is at its maximum in summer, and at its
minimum in winter.
  The amount of  rain  that  flows off the surface
depends on the  inclination  of  the ground, and
upon the character of  the  soil.   If  the surface
slope is steep, and if the ground is hard and rocky,
                                        1 
2
THE ELEMENTS OV HEALTH
most of the rain flows off the surface, and forms,
or helps to swell, the brooks, streams, and rivulets,
which uniting create rivers.
  Where  on the contrary the surface is flat, and
the ground is loose and porous, the larger portion
of the rain, which is not evaporated, sinks into the
ground or percolates.  It is owing to this passage
through the soil that the water is ultimately enabled
to become collected into the underground reservoirs,
which supply our wells and springs.
  Rain-water.—The collection of rain-water from
the roofs  of  houses is a matter of importance in
many rural districts, more especially where other
sources of supply are deficient in quantity, or bad
in quality.  Whilst stored rain-water is not very
suitable for drinking purposes, owing  to its becom-
ing stale  and flat when stored for any length of
time,  yet  it  is  extremely useful  for most  other
domestic purposes, on account of its softness.  By
softness is meant its freedom from chalk or other
salts which produce hardness.  Rain-water is soft
because it has not come into contact with the soil.
Most soils contain a considerable amount of chalk
or other  salts of lime—(chalk is  a carbonate of
calcium  or lime).   In  percolating  through  the
ground the water meets this chalk and dissolves it;
the chalk  is rendered invisible in the water, but it
is none the less there.  The water could not, how- 
WATER
3
ever, dissolve or take up the chalk unless there
were present in the interstices of the soil a  gas
called carbonic  acid.  This gas renders the chalk
soluble in water; if it is driven out  of the water,
as may be  done by  boiling the latter,  the chalk
becomes insoluble  again, and forms a  cloud or
turbidity   in  the  water,  which  cloud will  be
gradually deposited  on the bottom  and sides of
the  vessel holding the water.  It is this deposit
which forms the fur found in  kettles, boilers,  and
saucepans in which hard water has been boiled.
   As  is well known to most housewives, this fur
deposit is  highly objectionable.   It corrodes  the
metals on which it is deposited;  it  forms  a non-
conducting medium  between  the  source of heat
and  the substance  to be heated,  which  causes a
waste of fuel; it forms a coating on food  under-
going cooking,  which obstructs the  proper pene-
tration of  heat into  the interior  of the food, or
prevents solution of the  soluble  materials, when
this  is the result aimed at, as in the making of  tea,
broth, beef  tea, &c.   In hot-water pipes the lime
deposit tends to gradually narrow the calibre of
the  pipes,  and  such pipes may in  time become
completely blocked.   In boilers the lime deposit
forms a non-conducting lining, which when thick
enough, seriously retards the  passage of heat to
the water.   It is very difficult  to obtain  really  hot 
4
THE ELEMENTS  OF  HEALTH
water out of a furred boiler, and there is besides
the risk of an explosion.   If  the iron boiler-plates
are separated  from  the water by much fur, they
become overheated,  and  even red-hot.  Should
then a crack form  in the fur, the water comes
suddenly into  contact with red-hot metal, and is
converted into steam with  explosive violence.
  There is also  much waste of soap where hard
water is used for washing purposes.   A good lather
cannot be formed  until the lime in the water has
combined with certain of the constituents of the
soap, and so been separated from the water.   This
combination is  evidenced by the  formation  of
whitish curds  in the water.   The  production of
these curds shows the waste of soap.  If perfectly
soft  water is used, a good lather is very quickly
produced with  a  very small quantity of  soap.
This is the reason why in towns where the supply
of water is hard, most large laundry businesses
soften the water prior to use.
   In most large towns—especially manufacturing
towns—rain-water is too  dirty to  be used.  In
falling through the atmosphere the  rain washes out
of the air much of its soot, dust, and injurious
gases, and is consequently impure upon reaching
the  ground.   In country  districts the atmosphere
is purer, and the rain may be collected from the
roofs of dwelling-houses, stables, and greenhouses, 
WATER                   0
and  stored in tanks.  It should be stored in as
cleanly a condition as possible, and for this reason
it is advisable to reject the first portions of a shower,
which contain the washings of dirty substances off
the roof, and  to allow such water to run to waste.
This may be done by means of a rain-water  sepa-
rator, such as that invented by Roberts  of Hasle-
mere.  If rain-water is  collected in a dirty condi-
tion, the storage receptacle becomes  lined with a
foul sediment, which  putrefies, poisons the water,
and renders it unfit for use.
  Rain and other soft waters have a very consider-
able effect in dissolving metals  with which they
come into contact.  Consequently rain-water which
has been collected from lead roofs, or which has
passed through lead pipes, or been stored in lead-
lined cisterns, is very apt to contain traces of lead.
Even so small a quantity of lead in water as half a
grain to the gallon may produce in time symptoms
of lead poisoning amongst habitual water-drinkers.
  Streams  and Rivers.—Unless the stream from its
source has  passed through uninhabited and uncul-
tivated land, it is very liable to furnish water which
must in any case be regarded as suspicious from a
health point of view,  and in not a few instances as
dangerously contaminated.  Streams and  rivers
form the natural drainage channels of the localities
they traverse, and tend,  therefore, to receive the 
6
THE ELEMENTS OF  HEALTH
fluid refuse of habitations, villages, and towns on
their banks.  Human excreta will probably  form
some  part of this refuse, and in that  event the
possibility of the spread of typhoid  fever  through
the use of such water cannot be excluded.
  No one would willingly drink the water  from
grossly polluted streams, such as are to be found
in  many parts of Lancashire  and  Yorkshire.
The appearance alone of such  water is sufficiently
repellent.  But in the case of streams which  have
been previously contaminated with sewage or other
waste matters,  but not to an extent to be evident
to the  senses at  places  lower down  and several
miles from the point of pollution, it often becomes
an  important question  as to whether  the water
furnished by such a stream can be safely used.  A
perusal of the recent report of the Royal Commis-
sion on Metropolitan Water Supply (1893) would
lead one rather to think that an exaggerated value
had been  attributed to  the  possibly  dangerous
qualities  of such water.   The bacteriologists  have
tried to show that the bacillus of typhoid fever—
the  microbe   supposed  to  be causative of  this
disease—does not find  an easy  resting-place in
flowing water;  that it  is attacked by harmless
micro-organisms, normally present in  river water,
and eventually  destroyed ; or failing  such active
enmity, that  at least the typhoid bacillus is  less 
WATER
7
well adapted to such modes of existence  as  are
inherent  in  river  water,  than  the  harmless
species invariably  present there,  and  that  the
disease-producing organism in consequence ulti-
mately fails in the struggle for existence, and dies
out.
  Actual experience, however, seems to point more
to the  view that there is a danger in consuming
contaminated river water, especially at times when
the river is  in an  abnormal  state from  flood  or
from prolonged drought; and that it is never quite
safe to place at all times implicit reliance on such
water, unless it has  been previously  boiled, steri-
lised  by filtration,  or  efficiently filtered by sand
filtration on a large scale by a public company or
corporation.
  The mineral  ingredients  (hardness) of  stream
and river waters are various.   Near its sources, a
stream may consist of little but surface water, which
is soft, having merely run over the soil, and  not
percolated  through it. In the lower reaches,  the
water is usually much harder, the volume of sur-
face water  having been largely added to by springs
in the  bed  of the river—by water, therefore, which
has been in contact with the chalk and other salts
contained in considerable thicknesses of soil.
  Wells.—There are two kinds of wells—shallow
and deep.   As a general rule, to which, however, 
8           THE ELEMENTS OF HEALTH
there may be many exceptions, the water from shal-
low wells should be regarded with suspicion, whilst
that from deep wells may inspire confidence.
   In the subsoil containing surface or shallow wells,
the rain which percolates  from  the surface of the
ground through the porous soil, is prevented at a
certain distance down—usually from ten to thirty
or forty feet—from sinking deeper into the earth
by reason of a layer or stratum of impermeable soil,
such as clay, which does not permit water to per-
colate through it.  Sands, gravels, chalk, various
sandstones, and limestones, are more or less perme-
able to water, whilst clay, slates, granites, and other
hard rocks are impermeable.
   This underground or subsoil  water, so collected
in the porous soil on the underlying impervious
one, is  not  as a rule  stagnant,  but  is  moving
slowly  yet  steadily in one constant  direction—
namely towards  its outlet, which usually  consists
of a spring or springs at a lower level.  As those
who rely  upon wells are aware, the underground
water, which is visible or can be sounded in a well,
is not always standing  at the  same level.  As a
general rule,  to which of  course  there may  be
exceptions depending  upon exceptional seasons,
the level  of  the water in wells is highest  in the
early  spring  (February or  March), and lowest in
autumn (October or November).  The reason of 
WATER
9
 this annual fluctuation is  simply that  during the
 cold months  of the year there is but little evapo-
 ration, and much of  the rain  percolates into the
 earth, and so renews the volume of the underground
 water; whilst during  the warmer months, when
 evaporation is active, there is but little percolation,
 and  the  underground  water  being insufficiently
 replenished to make  up for the loss occasioned by
 the outflow in springs, its level  falls continuously
 until autumn is reached,  and percolation  recom-
 mences.
   The  water of  shallow wells  (Fig.  1)  having
 only percolated through a few feet (ten to thirty
 or so) of porous soil, since it descended as  rain on
 the surface of the earth, surface impurities lying
 on the ground, which  are taken up by the  rain,
 are  subjected to  but little  purification by  soil
 filtration before they reach the well.
   Again,  shallow wells in the neighbourhood of
 habitations  are  extremely likely to  receive  filth
 which  has  soaked into the porous ground from
 manure  heaps,  privy-pits,  leaky cesspools, and
 drains.  Liquid filth  of this character,  in its pas-
 sage through  small thicknesses of porous, sandy, or
gravelly soil, is  merely  strained of its grosser
impurities, and not filtered in any such way as to
render it innocuous.
  Indeed, the latest bacteriological research would 
Fig. 1.
 
WATER
11
appear to show that whilst the  bacillus  of typhoid
fever does not survive very long in ordinary  sew-
age, after its ejectment from the  human body, yet
should  this  sewage   be  filtered  through  small
thicknesses of soil, certain salts called nitrates are
formed  by  oxidation  of ammonia and  organic
matters  in  the  sewage, the  presence  of which
enables the bacillus to retain its vitality  for a con-
siderable period, and  to undergo  at the same  time
rapid and continuous multiplication.
   This may  explain why it is that polluted shallow
well waters  can retain for  such  long periods the
active infection  of  typhoid  fever—the  specific
typhoid  bacillus being favoured  in its growth  by
the  presence  of the nitrates derived  from the

   Fl<j. 1.—Shallow  Well, Polluted by Cesspool and Manure-heap.
   A. Porous gravelly or sandy soil.
   B. Underground or subsoil water.  The direction of the flow of
the water is shown by the arrows.  The main direction is from the
well to the house, but the depression of water in the well causes an
in-flow from every direction in a small circle surrounding the well.
   C. Impermeable soil holding up the subsoil water.
   D.  Well with hand-pump. The level of the water in the well
has been depressed by pumping.
   E. Leaky cesspool.  Liquid sewage percolates through the por-
ous soil and is drawn into the well.
   F. Closet of house, with drain-pipe leading to the cesspool.
   G. Manure-heap, from which filth soaks  into the ground. The
well is always liable to pollution from this source.  The cesspool
Boakage only  pollutes the well when the water level in it is de-
pressed by pumping. 
12
THE ELEMENTS OP HEALTH
filtered sewage, and being  sheltered in the depth
of the well from  the  action of sunlight—sunlight
being a very active and potent germ-destroyer.
   Another serious source of pollution is that aris-
ing from the proximity  of  graveyards and ceme-
teries to the well, and the consequent introduction
into the  subsoil water of matters derived from
decomposing animal remains.
   If  a shallow  well  is liable to pollution  from
leaky  sewers, cesspools, or  other  receptacles of
human waste substances, the extent of the pollution
is likely to be increased in proportion to the quantity
of water  withdrawn  from the  well.  When the
level of the water in the well is lowered by pump-
ing water out, the well acts as a focus of drainage
for all the water in the subsoil contained in a circle
of a certain size  around the well  as  a centre  (see
Fig.  1).    The  greater the depression of water
level, the  larger the radius of the circle which the
well drains.  It follows  from the above that a well
at a distance  from sources of contamination may
be supplying fairly good water as long as it is not
much drawn upon; but  that an increased demand,
by lowering the water level, may  have the effect of
bringing distant impurities within the area of its
influence, and so causing dangerous  contamination.
   The water of a well  is  occasionally submitted
to analysis, when the  house and premises supplied 
WATER
13
from this source are unoccupied, and consequently
no water is being pumped out.  The analysis under
these circumstances  may indicate  a fairly pure
water.  Subsequently the house being occupied,
and possibly illness having occurred, it is found on
analysis  that the water is polluted with sewage.
The natural tendency is to blame the first analysis;
but, as already indicated, the real explanation may
be that  on  the first occasion  the  water was not
subject to pollution,  whilst on the second occasion,
owing to altered circumstances, it was.
  A heavy fall  of  rain may  cause considerable
alteration in  the  appearance  of  the water of a
polluted  shallow  well.   During the dry weather,
the  sewage  which  percolates  into  the  well  is
probably so far filtered during its passage through
the porous soil, that the grosser impurities, which
render the  pollution evident to sight,  smell, and
taste, are removed.   The polluted well-water under
these circumstances may be clear, bright, sparkling,
and  pleasant to taste.   After  heavy rain-storms,
however,  the quantity  of liquid filth  finding its
way into the soil may be so excessive as to render
ineffectual the purifying filtering  powers of the
soil, with the result that unaltered sewage becomes
mixed with  the  well-water,  and  the latter  is
rendered turbid, foul smelling, and nasty tasting.
  A simple  test for a suspected water is to bottle 
14
THE ELEMENTS OP HEALTH
DISCHARGE PIPE!

Deep well and Borinc 
WATER
15
 some and place it in a warm dark cupboard for a
 day or two.   If the pollution is by sewage, and is
 excessive in amount, on removing the bottle, the
 water—originally clear and bright—may be found
 to have become turbid and evil-smelling. The reason
 of this alteration is that the microbes or bacteria,
 which cause  putrefaction  in organic substances,
 have been cultivated in the warmth and darkness,
 and multiplying in prodigious numbers have caused
 putridity in the organic matters contained in the
 polluted water.
  The water obtained from deep wells and  borings
 (Fig. 2) is usually  free  from organic matters,
 these having  been destroyed by  oxidation during
 the  passage of  the  water  through great  lengths
 or great thicknesses of porous soil, such as chalk
 or sandstone.   Oxidation in these porous strata of
 earth is  carried on for the most  part by bacteria,
 which in the presence of  air with its  contained
 oxygen break down or decompose complex  organic
 matters,  and resolve them into simpler  inorganic
 constituents, incapable of further change or disin-
 tegration.   The water from deep wells,  therefore,
 is much  more likely to be  pure  than that  from
shallow wells.
  To secure  this  result,  however,  deep wells
 (Fig. 2) should be protected from surface washings,
and  from soakage into them of  liquids from  the 
16
THE  ELEMENTS OP HEALTH
subsoil adjacent to the surface.  The upper portions
of deep wells,  then, should be lined with bricks
set in and rendered over with cement, to keep out
the surface and subsoil waters.
  Deep wells usually furnish water that is hard,
owing to its having taken up some of the earthy
constituents of the soil through which it has per-
colated.  This hardness is principally due to chalk
dissolved in the water, which  is called temporary
hardness, owing to the fact before stated that boil-
ing the water precipitates the chalk, and therefore
softens the water.   Deep well water may also, and
in addition, be permanently hard from salts of lime,
other than chalk, or salts of magnesia being present
in it, which are unaffected  by  boiling, and which
cannot therefore be got rid of in that manner.
  Many deep well waters are found to be remark-
ably  free  from microbic  or bacterial life.    They
are,  in fact, nearly or quite sterile, i. e. free from
living organisms.   They differ  in this respect more
especially from river waters, which even after sand
filtration are by no means sterile.   Sterility in a
water supply  is  doubtless  on most occasions  a
great hygienic advantage, inasmuch as to  certain
species of bacteria are  now ascribed the origin of
infectious diseases. Still it should be mentioned
that sterility in a  water supply is now  believed to
be on occasion a  distinct  disadvantage.   Should 
WATER
17
the bacillus of  typhoid be introduced into a sterile
water in the  depths of a well, as for instance
happened at Caterham,  in 1875, through the dis-
charges of a sick workman polluting the well-water,
then  the bacillus  has the power of undergoing
great multiplication, and causing large volumes of
the water to acquire infective properties.  Intro-
duced into non-sterile river water, and exposed to
the action of light  in open reservoirs, the bacillus
appears to be unable to maintain itself, owing both
to the antagonism of the microbes already existing
in the water, which is their  normal habitat, and
also to  the destructive effect of sunlight;  conse-
quently the disease-producing bacillus tends rapidly
to disappear.
   Springs.—The water  derived  from  springs
resembles that  of wells—a spring being merely a
natural outlet of a body of the same  underground
water  which  the  well  taps  in its  subterranean
depths.  The  so-called  "main  springs"  furnish
water from large underground reservoirs contained
in the fissures, cracks, and crevices of strata  of
large area  and considerable depth.  The water
from main springs usually flows all the year round,
although  with  seasonal  variations; whilst that
from " land springs " is derived from limited areas
of subsoil not far beneath the surface.  The water
from  such springs is very often polluted  in  the
                                       2 
18
THE ELEMENTS OP HEALTH
same  manner as are shallow wells, and may be-
sides cease to flow altogether during the summer
months.
                    Fig. 3.
Spring  issuinc  on  Side of Hill
     Springs, as a rule, are caused by the " cropping
•   out," that is, the appearance at the  surface of the
   ground, of the  impermeable strata  that hold the
   water up in  the porous strata above  them (see
   Fig.  3).   Springs are very commonly found on
   hill sides, in  valleys  bordered by hills, at the
   feet of cliffs on  the  sea-shore, and in  the beds  of
   rivers.
     The perennial springs, which flow all the year
   round, although usually with diminished volume in
   the summer, supply for the reasons above stated
   water of more constant purity than  the  inter-
   mittent  springs which are  dry  in  summer-time.
   The temperature of the water of these deep-seated 
WATER
19
springs is also remarkably uniform  both summer
and winter, the  underground reservoirs  being
comparatively unaffected by atmospheric seasonal
changes, owing to the  great  depth of intervening
soil.
  Public Water-supplies.—There is a considerable
advantage to the health of the community in the
supply  of  water by a public water company or
municipal corporation, as opposed to the private
supply, whose source  is too often liable  to con-
tamination.  Half a century ago, large sections of
the  community  derived their water supply from
shallow wells situated  on private premises, from
stagnant ditches or ponds into  which all kinds of
refuse found access, or from filthy streams.  To-day
such sources of supply  are  becoming much less
common; and many of our chief industrial centres
have acquired sources of water-supply which are
not only adequate  for the needs of  their  present
populations, but are likely to prove  sufficient for
the wants of growing populations for generations
to come.
  Thus Dublin is supplied with water from gather-
ing-grounds and a large "impounding reservoir " at
Vartry amongst the Wicklow Hills, twenty-six miles
from the  city.   Glasgow takes water from Loch
Katrine, thirty-four miles from the city.  Man-
chester has lately obtained a new source of supply 
20          THT: ELEMENTS OP HEALTH
from  Lake  Thirlmere.    Liverpool by  immense
engineering works  has  impounded the waters of
Vyrnwy  amongst the Welsh  hills,  creating  an
artificial reservoir four and three quarter miles in
length,  and  conveying  the  water a distance  of
sixty-eight miles.  All these waters are pure, soft,
and well fitted for all domestic and manufacturing
purposes,  although  some of them  are  slightly
peaty, the peat being derived from the gathering-
grounds of the water.
  The chief danger of a public water-supply lies in
the disastrous consequences liable to ensue upon the
introduction of infectious  matter into  a  reservoir
or distributing main.  Under these circumstances
a  wide-spread  epidemic  may  arise,  involving  a
considerable  section of the  water  consumers—an
epidemic which would have been impossible under
a system of separate supplies from  private sources.
What are  known as water  epidemics of typhoid
fever are now unfortunately sufficiently familiar.
Such wide-spread epidemics were unknown, or at any
rate unrecognised, before the days  of public water
supplies.  On the whole, however, the balance of ad-
vantage is decidedly in favour of the public supply.
  Constant and Intermittent Supply.—Public com-
panies either supply their customers with a constant
flow  of water into their houses, or intermittently—
that  is to say, the water is only turned on from the 
WATER
21
mains into  the houses at intervals, usually once
or twice a day.
   The great advantage of the  constant service  is
that no  storage  is required in the houses.  The
only cisterns necessary in a house  with  constant
service are those required to supply water-closets
and kitchen boilers.   The water is therefore de-
rived straight from the mains, and  is not deterio-
rated before being consumed by  long storage  in
cisterns or water butts.
   Cisterns.—Water which is stored in cisterns be-
comes flat and insipid, and is in fact less refreshing
than  that drawn direct from the  mains.   Recent
observations also show that the microbes  in water
undergo great multiplication when water  is at rest
in cisterns or tanks.  We are not aware at present
of the precise influence such excess of microbes  in
drinking  water may exert upon the human frame.
The majority of them may be harmless, but we do not
know if the products of their growth are  as inno-
cent ; nor do we know that harmful microbes may
not be included amongst  a  crowd of harmless
species.   On the whole it is better, because safer,
that water should be consumed in as nearly sterile a
state as possible, so that the risk of the introduction
of harmful organisms, or of the injurious products
of any organisms,  may be reduced  to the nearest
attainable minimum. 
22          THE ELEMENTS OP HEALTH
  Such disadvantages  apply to storage under any
conditions, even  the best;  but experience shows
that storage in houses is often so carried out as  to
introduce dangers of pollution which are  strictly
preventable.
  Cisterns are often placed in  improper places.
The main cistern  of  a house, used to  supply water
for all domestic purposes, may be found inside a
water-closet, where  it  is liable  to be reached by
unwholesome gases;  or under stairs or floors, where
dust and dirt fall into it;' or placed in inaccessible
positions, where access for the necessary cleaning
is impossible;  or without a cover in the open air,  so
that soot, dirt, and filth of  various kinds  find an
easy entrance  into the  water.
  There is  another source of  danger  to which
special attention  should be  given,  namely, the
direct  connection of the main  or drinking-water
cistern of a house to the water-closet apparatus  or
to the drains  by  means of a pipe or pipes (see
Figs.   17  and  18, p. 74).   Sometimes it  will be
found  that the overflow pipe  (the  pipe used  to
carry   away water when the cistern is  overfull)
is  connected  to a drain or a  soil-pipe—(a  soil-
pipe being the pipe  used to connect a water-closet
with an underground  drain).  In such cases, foul
air from the  drain  may escape  immediately over
the surface of the water, between the water and 
WATER
23
the cistern-cover.   In this  way the water  may
become  dangerously polluted with  air from the
drain, and with the injurious matters such air may
contain.
  It  frequently happens  that the  main cistern is
used to supply water to a water-closet for flushing
purposes.  In  these  cases there is great risk of
the water in the cistern becoming polluted by bad
air from the closet, if the  valve—which must be
opened to allow water to reach the closet-pan—is
in the cistern  itself.   The valve is in connection,
by means of wires and levers, with the handle of
the closet, and, when  opened, air from the supply-
pipe of the closet is apt to pass back through the
water of the cistern, and so cause it to be polluted.
There is less risk  of  such an  occurrence when the
valve is on the supply-pipe close to the closet-pan,
for in this case the supply-pipe contains water and
not air, and therefore presents an obstacle to the
passage of air from the closet-pan up to the cistern.
  If cisterns are required in a house, the following
simple rules should be carried out.  (1) The cistern
should be placed in an accessible position; it should
be covered with a well-fitting lid; and situated so
as not to  be  exposed to foul air, dust, dirt, or
vermin gaining access to it.  (2)  The overflow pipe
should not be connected with any part of the
drainage appliances of the house, but should be 
24
THE ELEMENTS OP HEALTH
carried through an outer wall or the roof, so as to
end  in the open air, and serve as a "warning"
pipe—a pipe, that  is to  say, which gives warning
that the cistern is  overfilling, and that waste of
water is  occurring.   (3) Water-closets should not
be  supplied  directly from  the main cistern,  but
small flushing cisterns, each cistern containing a
few  gallons  of water, should  be used to  supply
the water-closets; these small  flush-cisterns being
themselves  supplied with water from the main
cistern.  The rule  should be enforced that every
tap in a house must be regarded as a drinking-
water tap.   It may, at  least, be so used at times,
although  perhaps  not  habitually.   The  cisterns
supplying taps should be separate from those used
to flush water-closets.  (4)  The cistern should be
periodically cleansed, twice a year at least; and in
the  case  of  lead-lined  cisterns, care should  be
taken  that  any coating lining  the metal is  not
removed, so as to avoid the subsequent exposure
of a bright metallic surface to the  action of the
water.
  The material of  which the cistern is made, is
perhaps of  less importance than the  conditions
above  stated.  Galvanised iron  cisterns are now
most largely used;  stoneware has been lately intro-
duced  as a  material for cisterns;  whilst brick
cisterns lined with cement are especially useful for 
WATER
25
the underground  storage  of rain-water.    Slate
cisterns with cement joints are  employed in some
places.   Lead-lined  cisterns are,  on the  whole,
better avoided, although it must be stated that for
waters of medium  hardness, like the Thames water
supplied to London, which have a comparatively
slight solvent action on lead, there is  no great risk
in the use  of old  lead cisterns,  whose surface has
become adequately covered by a protective coating
from  deposited salts.
  In  speaking of  the constant service of water, it
has been  mentioned that small flushing  cisterns
are required for the water-closets.   It should be
an invariable rule in every household, which has a
constant water  supply, that water-closets are not
to be directly connected to the house water-pipe,
without the intervention of a cistern.  The neglect
of this observance has led to outbreaks of  disease,
owing to liquid filth or foul air being sucked into
the main water-pipes, during intermissions in the
service, through pipes  in houses connected direct
to foul and obstructed water-closets.   It is now an
ascertained  fact  that  main  water-pipes  under
certain circumstances, as when emptied of water,
tend  to  suck in air or water from the ground, if
there are  leaks in the  pipes there, or from house
pipes if there  are  no leaks in the  underground
mains,  and so the  desirability of not connecting 
26
THE ELEMENTS OF HEALTH
the house-pipes  with  any receptacle liable  to
contain foul matters is evident.
  Where there is a constant supply of water, it
will occasionally be noticed that the water drawn
from the tap in the early morning is milky looking
from the presence of innumerable little bubbles of
air;  these gradually rise to the top of the water
and disappear.  They merely indicate that by some
means air has found its way into the water-pipes,
and has become churned up with  the  water.  As
a rule, they do not  indicate  any  dangerous con-
tamination ; but should the water smell of coal gas
or sewer gases, it should be rejected at once, and
the attention of the water company's officials should
be drawn to the fact.
   To  avoid  the risk of  drinking water containing
traces of lead, the water which  has been at rest all
night in the lead pipes should invariably be allowed
to run to waste.  A gallon or so may be got rid of
in this way, and then it will  be right to  assume
that the water  drawn off has arrived  direct from
the iron street mains.
   Purification of Water.—When water is raised to
the boiling point for a few minutes, all microbes or
germs present in it are destroyed.   It is possible
that a few of the spores or immature forms of these
microbes may remain alive in  the  water;  but for
all practical purposes the water may be regarded 
                      WATER                   2 7
 as  sterilised.   The harmful or disease-producing
 microbes are probably killed with greater rapidity
 and certainty than the harmless species.   In this
 case, at any rate, experience coincides with theory
 in agreeing that boiling renders a water harmless—
 a water, that is to say,  which if drunk unboiled
 might well be credited with the  capacity to pro-
 duce disease.
  Water which has been  boiled is not pleasant  to
 drink, owing to the  loss of its aeration, any gases
 dissolved in the water having been expelled by the
 boiling.   This  flatness may be improved by allow-
 ing the water to flow—a drop at a time-—from one
 vessel to another.   In falling through the air, the
 drops of water become aerated, and palatability is
 restored.
  The softening of a hard water for domestic use is
 occasionally desirable.  This can be  accomplished
 by boiling and getting rid of the temporary  hard-
 ness, as previously described; but far more  easily
 by the use of one of the softening  powders now
 prepared by several manufacturing  firms.  These
 powders consist of slaked lime with  a certain pro-
 portion of soda.  When added to the water, they
 cause a precipitation  of the chalk dissolved in  it,
and thus get rid of the temporary hardness  in the
 same way as boiling does.  This softened water
 should not be  used  for  drinking, unless special 
28
THE ELEMENTS OP HEALTH
precautions have been taken to add the powder in
exact proportions ; otherwise some excess of soda
or lime may remain in solution, which might impair
the potability of the water.
  Domestic Filters.—These contrivances are perhaps
on the whole more often a source of mischief than
of benefit.  A  neglected filter is likely  to  add
impurity to a water  passed  through it; and it is
certainly true that filters are more often neglected
than kept in  a proper state of cleanliness and re-
pair.  These remarks are especially applicable to
cistern filters, which when once fixed are often left
for years in position, their very existence being
forgotten.
  The general impression in the public mind is
that any sort of domestic  filter is  capable of  ren-
dering a water fit to drink. There is no evidence to
support this view except in the case of the "sterilis-
ing filters," which do undoubtedly—for a time at
any rate—remove all living microbial life in  the
process of filtration.  It  is, however,  conceivable
that there may  be existent  in a water chemical
poisons, the  result  of  the  activity of  microbes,
which the sterilising filtration does not keep back.
In the case of the ordinary carbon powder, asbes-
tos, and block filters—comprising the vast majority
of the domestic filters made and sold in this country
—it cannot be claimed even that there is any sterili- 
WATER
29
sation, so that microbes of all kinds may be present
in the filtered water to the same extent as they are
in the unfiltered water.
                     Fig. 4.
Section or  Berkefeld  Filter
  The sterilising  filter  was  first  introduced  by
MM. Pasteur and Chamberland ; a similar filter has
since  been  constructed  by  Berkefeld  (Fig.  4).
In these  filters water is  passed under pressure
through cylinders  of very  fine porous ware.   So
fine are the pores of the ware, and so intricate are
the passages through it, that not even  the most 
30
THE ELEMENTS  OP  HEALTH
minute of the known micro-organisms are able to
pass through.  Scientific  opinion  is not yet in a
position to assert that the sterilisation effected  by
this filter is as efficacious as the boiling of a water.
Still the sterilisation may  be regarded practically
as removing the  chief sources of danger from a
suspicious or polluted water.
  Quite recently an elaborate and very important re-
search has been conducted by Drs.  Sims Woodhead
and Cartwright Wood into the relative  efficiency
of water filters in the prevention of infective disease.
The results obtained,  after careful testing of the
domestic filters obtained from most of the filter manu-
facturers in this  country, show that no protection
what ever is conferred by the use of these appliances
against the  passage of disease  germs  from the
unfiltered into the filtered water;  and that conse-
quently the  claims advanced by the makers of
these filters  to  the  effect that  their appliances
safeguard their owners  against  "Typhoid  fever,
Cholera, and Blood-poisoning," are absolutely un-
reliable and unwarranted.
   In  some respects the use of these filters even
enhances the danger arising from the consumption
of infected water, inasmuch as many of the microbes
are temporarily arrested in the filtering medium,
and continue  to  pass through the medium into
the filtered water for a week or even longer after 
WATER
31
they have been deposited.   Thus a water-supply
containing, suppose, infectious matter on  one day
only, would,  if drunk unfiltered, endanger the
health of the consumers on that day only; but if
passed through a filter before  being  consumed,
the use  of  the pure  water subsequently passed
through the same filter would endanger the health
of the consumers for a further period of seven or
more days subsequent to the day when the  filter
was infected, owing to the pure water  washing
arrested  infective  microbes through  the  filtering
medium into the filtered water.
  No doubt the general verdict of those who read
these scientific revelations  will be that domestic
filters  should  rather  be  regarded  as  domestic
enemies than as friends to health, for they promise
what they cannot perform, and thus engender a
false sense of  security.
  The process  of purification carried out by the
London (Thames) Water Companies, is very fairly
effective in  depriving the  water of  the microbes
contained in it in its unfiltered condition.   In the
large subsidence reservoirs, into which  the water
is  led  from  the river, much  of the  suspended
matter is deposited, carrying with it vast numbers
of micro-organisms.
  This clarified water is  next  passed  through
filter-beds (Fig. 5) consisting of about  three  feet 
32
THE ELEMENTS  OF HEALTH
of fine sand lying upon layers of gravel, fine  above
but coarse below, in which are the mouths of the
outlet  pipes  to convey the water to the pumping
station.
  Upon the top of the sand-filter, after it has been
in use some days, a layer of gelatinous matter forms
which is very retentive of microbes.  It is to this
gelatinous  substance  that is now attributed the
Fig. 5.
Surface of water
■ fM&S'i

£ WATER

< CCLATiNOUS OtPOSiT

h
" FINE SANO

X
1 FINE &RAVEL


£ COARSE GRAVEL

 6 INCH PIPES
 WITH OPCM J
 CONCRETE
 CROUNQ
Section  of Sand  Filter-Bed
chief effect of sand filtration in reducing the num-
ber of  microbes in the filtered water—a reduction
which  amounts  on the average to about 98  per
cent.,—that  is  to  say,  only  about  2  per cent.
of the microbes to be found in the unfiltered water
are present in the filtered.   The gelatinous layer
which forms on the surface of the sand, and which
entangles in its  meshes the microbes, is  derived 
WATER
33
 from the organic matter strained out of the water,
 and it is no doubt very largely composed of micro-
 organisms itself.
   Inasmuch as this gelatinous layer does not form
 for at least two days after the sand filter-bed has
 been brought  newly into use,  it is  obvious that
 until this interval has elapsed the purification  is
 not  satisfactory.  We also know from actual ex-
 perience that in times  of flood, when the  river
 water is very turbid, the filtration is  not effective
 in removing suspended matters, including microbes,
 as under these  conditions a cloudy and coloured
 water is  very  often  distributed  to the  con-
 sumers.
   The chief danger to the water-consumer  would
 therefore appear to be  during times  of floods, or
 after prolonged frost, when the powers  of  the
filtering  beds are overtaxed or disturbed—these
powers,  as we now know, being largely dependent
upon biological processes.
3 
34
THE  ELEMENTS OP  HEALTH
                 CHAPTER II

                 DOMESTIC REFUSE
Ashpits and dustbins—Privies, middens, and cesspools—Pail, ash,
   and earth  closets—Water-closets—Soil-pipes—House-drains:
   Testing drains—Waste-pipes—Gullies and bell-traps—The
   flushing and cleansing of drains.
  The domestic refuse  of  houses is  composed of
the following matters :—Excretal refuse, i. e. faeces
and  urine;  household slops or soapy water used
for  washing, mixed  with urine;  kitchen  waste
waters,  containing organic  matters from food,
grease, and sand, this water being  often at a high
temperature;  bones and scraps of food; broken
pots and pans, dust, ashes, cinders, and rubbish of
all kinds.   Some of these  matters are in a liquid
condition, whilst  others are  more  or less solid.
Some, again, such  as the excreta, the refuse food,
fat, and  bones,  are prone to rot and decay;  whilst
other matters,  such as  cinder refuse,  are inde-
structible, except by burning.
  Prompt removal  of  the  matters which are liable
to decay is essential for  the maintenance of a good 
DOMESTIC REFDSE
35
 standard of  health.  Organic filth in the process
 of rotting is attacked by the microbes of putrefac-
 tion, which  are universally present  in  air, earth,
 and water.   The role of these microbes is to disin-
 tegrate  or  resolve complex  organic bodies into
 simpler elements;  but  in this very necessary pro-
 cess  gases  and vapours are  given off which  are
 distinctly injurious to  human life.   The function
 of the microbes is an important and necessary one,
 for  without  them  perished  animal  substances
 would remain for ever in  a  useless  condition,
 serving merely to litter up the surface of the earth.
 By the aid, however, of the microbes of putrefac-
 tion, animal matters are changed into those simpler
 substances which form the  nourishment of plants,
 these in  turn supplying food for animals, and thus
 the natural balance is preserved.  It will now be
 apparent why the  prompt and regular removal of
 refuse matters from houses is so essential for the
 preservation of health, and why the disposal of
 sewage and such like  refuse on land is  so largely
 carried out in modern sanitary systems.
  In  many parts of the country, at  the present
time, excretal  matters, together with the liquid
slops  and waste waters, are  carried away from
houses by means of water,  through  the  agency of
water-closets, drains, and sewers.   The great ad-
vantage  of  this water-carriage system is at once 
36
THE  ELEMENTS OP HEALTH
evident,  for the foulest  and most  noxious of the
refuse material of the house is immediately removed
out of the vicinity of the dwelling by means of the
drains.   In many places still, however, this water-
carriage  system  is not in operation; and  here we
find that the excreta are collected  in pails, tubs,
privy pits, or cesspools.  In these  receptacles ex-
creta  and  other waste matters  are retained for
periods varying  from a  week to months,  or  even
years. The odours  of  putrefaction are seldom
absent from such dwellings  or their surroundings,
and the inhabitants must perforce live in an atmo-
sphere more or  less pervaded   by unwholesome
effluvia.
  We are, therefore, in a position to affirm  that the
first principle  of  sanitation  requires that all  such
refuse matters as are liable  to ferment and decay
should be  removed  from the  neighbourhood  of
dwellings with the least possible delay.
  Ashpits and  Dustbins.—These receptacles are
intended  to contain the solid refuse matter of the
house until such time as it can be taken away.
They  are not meant to  receive  excreta or liquid
refuse of any kind.  Even as regards solid refuse
care and  discrimination should be  exercised  as to
the kind  of matter put into the dustbin, if nuisance
both  to the house and  its  neighbours  is to be
avoided.   Bones, fat, and  waste food scraps will 
DOMESTIC REFUSE
37
 ferment and rot  in the dustbin, especially during
 the warmer periods of the year.  As far as possible
 these matters should be  kept out of  the  dustbin,
 and  what cannot be  destroyed by  heat in  the
 kitchen fire should be placed in a galvanised iron
 pail with an  air-tight  lid, and taken  away  daily.
 Dust, ashes, cinders, and dry rubbish are the matters
 which the dustbin may properly contain.   If great
 care is  taken in this direction, the dustbin is little
 likely to become the serious nuisance so commonly
 experienced.  But even then a frequent emptying
 of the contents is desirable.   How often this should
 be carried out depends on circumstances, but in any
 event the contents should not be  allowed  to accu-
 mulate for a longer period than a week.  It is per-
 haps hardly necessary to insist that infectious rub-
 bish from the sickroom  should be burned,  and
 never thrown into the dustbin.  Such a proceeding
 is now in London, under the Public Health Act, an
 offence  punishable by fine.
  A galvanised iron pail with a tight-fitting lid is
 far preferable to  the  old-fashioned brick dustbin.
 In the first place it is desirable to have a small re-
 ceptacle,  so that its  contents  may be frequently
 removed.   The brick dustbin was generally  made
 of large capacity, in order that a frequent  removal
 might not be necsssary.   Again, bricks are porous
and absorptive of foul  matters, so that even  when 
38
THE ELEMENTS OF HEALTH
empty the  brick dustbin is by no means inoffen-
sive.  They are also difficult to empty ; they are not
easily cleansed; and the wooden cover which secures
the dryness of the contents  is very often out of
place, or not to be found.
  It is a matter of considerable importance that
the contents of the dustbin  should be kept dry.
Fermentation and decomposition of organic matters
proceed at  the greatest rate when there is abun-
dance of moisture, and when the temperature of
the air is sufficiently high.  We  cannot alter the
temperature, but it is possible to exclude moisture,
and thus deprive  the  microbes of one of the ele-
ments necessary for their growth and life.
  The advantages of  the  galvanised  iron pail are
its small  cubic capacity, the non-absorptive charac-
ter of the  material of which it is  made, and the
facility with which it is kept covered and its con-
tents sealed up.  It can, besides, be carried bodily
to the dust cart into which its contents are to be
shot, and can be thoroughly cleansed when empty.
The process  of digging out the  contents of the
brick dustbin was always an offensive  one;  and
when situated under the windows of a house, as they
often were, the dust and effluvia were apt to find
their way in through the windows.
   The ultimate disposal of the dustbin refuse is
rather outside the scope of this little treatise; but 
DOMESTIC REFUSE
39
it may be well to remark  that house refuse, with
its many potentialities  of mischief,  ought to be
cremated, i. e.  destroyed by fire.  It  certainly
should not be mixed with manure and sent away
into the  country, to be  spread upon fields in the
neighbourhood of villages, as is still far too fre-
quently done.  This practice has led to outbreaks
of  sore  throat and  diphtheria  amongst  village
populations, who certainly should not be exposed
to sources of danger not of their own manufacture.
Nor is the process of sorting out the filthy refuse
into its  constituent parts, as conducted in diist-
yards  by both men and women, an occupation to
encourage  from  the  social  or hygienic  point of
view.
   Privies, Middens, and  Cesspools.—It is unneces-
sary to say much about  such receptacles for filth,
inasmuch as they are now condemned by all sani-
tary authorities, and  replaced by improved forms
of  ash  or earth  closets  wherever  found.  The
common form of privy,  midden, or cesspool  is a
hole of considerable  size excavated in the earth,
and lined or  not, as the  case may be, with bricks
or bricks set in  cement—more usually, perhaps,
the former than the latter, as the porous  unlined
pit allows the liquids  of the sewage to escape, and
so requires emptying  only at long  intervals.  It is
a noteworthy fact that the liquids of house sewage 
40
THE ELEMENTS OF HEALTH
 form by far the larger proportion of its bulk, con-
 sequently the solids left behind in a privy-pit after
 the escape of the liquids, accumulate at so slow a
 rate, that a long time must elapse  before the pit
 becomes filled.
   As previously  described in  the  chapter on
 " Water," the  foul  liquids escaping into  the soil
 frequently cause pollution of water supplies, and
 necessarily contaminate the ground in the neigh-
 bourhood.   In  addition  there is  contamination  of
 the air  from the large  accumulation of putrefy-
 ing filth, and this is invariably increased when the
 contents of the pits are being dug out for removal.
 In the case of the poorer parts of some towns, the
 privy contents have to be carried in pails through
 the houses, there being no side or  back entrances to
 the yards where the privies are situated.
  There is  less objection to properly lined and
 constructed cesspools situated  at a  distance from
 houses, wells, or streams.  Where the cesspool con-
 tents can be used on garden  ground, and where
 there is no danger of pollution of water supplies,
 the cesspool system has its advantages; but still it
must be admitted that the principle of the cesspoo
violates the elementary  rule that  the fertilising
matters  of sewage should  be returned to  the soil
with the least possible delay, and  should not be
allowed  to ferment and putrefy in enclosed recep- 
DOMESTIC REFUSE              41
tacles.  If cesspools are employed in country houses
with gardens, they should be situated at a distance
from  the house;  they should be  constructed  of
puddled clay, brick, and cement, so  as to be im-
permeable to liquids, and they should be ventilated
by a good-sized pipe carried up a tree.
   In  many country places it is  possible to apply
the sewage at once to  the land, upon specially pre-
pared  filter-beds,  or  by means of sub-irrigation,
and thus avoid any necessity for  cesspools.
   Occasionally cesspools are found under the base-
ments of houses.  Originally constructed, perhaps,
before the existence of public sewers in the streets,
or before these sewers were used for  the reception
of house  sewage,  they will often be found to be
connected, by means of an overflow pipe, with the
sewer under the street, this pipe having been intro-
duced after the date at which it became lawful to
connect house-drains to public sewers.  A cesspool
so situated under a house,  which is never emptied
or cleansed, and which is in direct connection with
a public sewer, is likely to prove  a very serious
source of mischief, and to  be productive of grave
illness amongst the occupants.  The evil is the
greater from the  ignorance of its  cause, for the
existence  of such  old  cesspools under the base-
ment is usually quite unknown and unsuspected.
  Pail, Ash, and Earth Closets.—The moveable pail 
42
THE ELEMENTS  OP HEALTH
for the reception of excretal refuse is  a  great
improvement  on  the  fixed  and  leaky privy or
midden.   A galvanised iron pail or a stout oak tub
is  placed  under the closet seat;  when full it  is
covered with  a tight-fitting lid, and its place  is
taken by  a clean  empty  one, the full pail  being
removed bodily to the place where it is to be emptied
and  cleansed.   It is very essential that the con-
tents of the pails should be kept as  dry as pos-
sible, to prevent fermentation and the disengage-
ment of  foul  odours.   For  this reason  slops
and  waste waters must on no account be thrown
into  pail  closets—not even the urine  of chamber
slops.
  It is best also to ensure the dryness of  the con-
tents by  the  use of ashes,  or dried and  sifted
earth.  Ashes and cinder  refuse are very absorptive
of moisture, so that  a small  quantity added after
each  use  of  the  closet  tends  to  keep  the pail
contents dry.   Dry sifted earth is also very useful
for this purpose.  Faecal matter, with which dry
earth has been mixed, becomes not only inoffensive,
but after a short time even unrecognisable as such.
It is no doubt due to the micro-organisms contained
in the earth that this result is secured—but, be  it
noted, without setting up putrefaction or producing
offensive effluvia.  The resulting " compost" pro-
duced by the mixture of  earth with faeces, forms a 
DOMESTIC REFUSE
43
good garden mould  for potting out plants, but is
by no means a rich or valuable manure.
  Special closets are manufactured for use with
ashes or dry earth.   The design of these closets
is to apply  a measured quantity of ashes or dry
earth at each use, and for this purpose the handle
of the closet is in connection with a hopper behind
and above the  seat, which  delivers the regulated
quantity into the pail on the  handle being raised
(Fig. 6)".
                     Fig. 6.
            Ash or  Earth  Closet
  There is wisdom in not allowing pail, earth, or
ash-closets to  be placed  inside  houses.   If so
situated, they  are very  frequently  made the re-
ceptacles for slops, and then become an unmitigated 
44
THE ELEMENTS OF HEALTH
nuisance.  There is, besides,  always some  odour
from these closets, even under the best of circum-
stances.  Their proper place is out of doors, where
the escape  of  foul  gases is  least  likely  to  be
productive of nuisance.
  Water-closets.—The essentials of a good form of
water-closet  may be  given  as  follows: — The
apparatus should be simple and inexpensive;  all
parts of the pan or basin,  in which the excreta
are deposited, should  be  capable  of being easily
and well flushed by water; there  should  be  no
confined  air-space  between   two  water-seals, in
which foul gases can accumulate;  and the pan or
basin of the water-closet  must be connected with
an efficient trap or water-seal, to prevent the pas-
sage of foul air from the soil-pipe or drain into  the
house.
  The form of water-seal now most largely used
is that known as the siphon trap.   This is merely
a pipe  bent into the  shape of the  letters  s or p
placed sideways, the curvature of the pipe retain-
ing sufficient water to prevent the passage of  air
through it.   Although the water-seal form of trap
is cleanly and simple,  it is liable to certain disad-
vantages.  Thus, if the water-closet is not  in use,
the water in the trap may evaporate, and the seal
be rendered no  longer effectual in preventing  the
passage of  air.   Again, the water in  the  trap is 
DOMESTIC REFUSE
45
liable to be sucked out into the soil-pipe or drain
by what is known as " siphonage."  It will  be
necessary to recur to this subject again in speaking
of soil-pipes.
  A good  form of water-closet is that known as
the "short  hopper" or "wash down" closet (Fig. 7).
The pan  or basin is  made  of china  or white-
ware, well  glazed on the  surface, so as to present
a hard, smooth, and shiny surface, readily cleansed
by  a flush of  water.  The  top  of  the  basin is
provided  with a  flushing rim, which  allows the
water from the flushing cistern to  flow all round
the  basin,  and to descend with impetus into the
trap at the bottom of  the basin.  The back part
of the  basin is constructed  so as  to be nearly
vertical, whilst the front portion slopes  forward.
This construction secures  that  the  faeces are
deposited in the  water of the trap,  and not upon
the  sides  of the  basin,  and  thus  the  closet  is
rendered cleanly  in use.   A closet  of  this kind
should not be  boxed in with woodwork; the seat
should  be  hinged at the back, so that it can be
turned up, and thus expose the space between the
seat and the floor, which is so often  the receptacle
of filth and dirt.   Some  manufacturers  supply a
closet of this class suspended from iron brackets
let  into the  wall,  so  that  no part of the closet
apparatus rests upon the floor.  By this arrange- 
46
THE ELEMENTS OF HEALTH
ment the housemaid's broom and duster has access
to every part of the water-closet floor, and cleanli-

                   Fig. 7.
           Wash-down Closet
    with  water-waste  preventer
ness  is possible in  the  place where  it is most
required. 
DOMESTIC REFUSE
47
  Wherever it is possible, water-closets should be
placed against an outside wall, so that they may
be  ventilated into the outer air.   Water-closets
without external light and ventilation are usually
a nuisance, as the foul odours generated in them
find their way into  staircases  and living  rooms,
and the darkness of the closet engenders neglect,
and its consequence, dirt.  In new buildings the
water-closet should not only be placed  against an
outside wall, but should also be approached by a
lobby  with  swing doors of entrance and  exit,  so
as to cut off direct access of air from the closet to
the house.  This  lobby should  be ventilated by
windows  opening into the outer air  (Fig. 8).
                      Fig.  8.
              Plan  of W.C.
        in  House  with Approach Lobby

  The common Pan and Container closet (Fig. 9),
which has been so  largely used, is an insanitary 
48
THE ELEMENTS  OF  HEALTH
form, on account of the filthy condition the con-
tainer gets into after prolonged use.  The container
is below the pan, which swings into it, and much of
                     Fig. 9.
Pan and Container  Closet with  D-trap
its interior surface is never flushed by the descend-
ing water, although it becomes  much  fouled by
the splashings of excreta.  The D-trap to which the
outlet  of  the container is connected, is also an
insanitary appliance.  It is not properly cleansed
by the flushing water, and in time becomes silted 
DOMESTIC REFUSE
49
up  with filth, which  putrefies and gives rise  to
offensive gases.   These pan-and-container closets
are always a nuisance, for when the handle of the
closet is pulled up, and the pan depressed into the
container, the foul gases which have accumulated
in the container and D-trap escape into the water-
Fig. 10,
                Valve  Closet
closet apartment, and  so find their  way into the
house.
  The Valve closet (Fig. 10) is a great improve-
                                      4 
50
THE  ELEMENTS OF HEALTH
ment on the pan closet, and is now largely used in
the better class of houses.   Being fitted  with
rather  delicate mechanism it requires care in use,
and is  not well  adapted  for working class dwell-
ings, where rough usage  is often experienced.
  The  "Wash-out"  closet (Fig. 11), another form
                     Fig. 11.
               Washout Closet
in common use, is not so cleanly as the wash-down
or short hopper previously described.   It is not
so well flushed with a small quantity of water, and
the entrance to the trap below the basin is apt][to
become much soiled. 
DOMESTIC REFUSE
51
  Whatever  form of  closet is used,  the  cistern
required to supply the closet with flushing water
should always be separate and distinct  from the
main  or drinking-water cistern.  For closets of
the short hopper type,  what are known as " water-
waste preventers " are now commonly used.  They
hold from two to three gallons of water, which are
discharged at once into the basin of the closet by
a short pull on a  chain.   This chain is connected
to a siphon action arrangement in  the cistern by
means of a lever, and the pull on the chain  sets
the siphon in action.  Water companies now insist
on these "check" cisterns, as they are often called,
being used, because they prevent the undue waste
of water.  The rapid discharge of the contents
by a short pull on the chain is also an advantage,
as it  ensures the proper flushing of the closet at
each  use by a regulated amount of  water.   These
water-waste preventers should be fixed at a good
height above the seat of the closet, and the  supply-
pipe  should be at least 1£ inches in diameter, in
order that the water  may  enter the closet basin
with  sufficient impetus and velocity to  cleanse it
and the trap below it.
  Soil-pipes.—The soil-pipe receives the discharges
from  the upstairs water-closets, and conveys them
by a greater or less length of vertical pipe to the
underground  drain.   The  best  material, on the 
52          THE ELEMENTS OP HEALTH

whole, for  soil-pipes  is  rolled and drawn lead,
the joints  between  different lengths being made
with solder,  i.e.  what  are  known as  "wiped"
joints.  The  advantage  of lead  as a  material is
that it has a smooth  surface, to which the filth
of sewage does  not readily  cling.  These pipes
are usually made 3£ or 4 inches in diameter,  the
branches to the water-closets  being of  the same
size.
  It is  much to be  preferred that the soil-pipe
should be fixed outside  the house, instead of in-
side, as is so often done.  If  there  is any defect
in an internal soil-pipe, the foul air from the pipe
escapes into the house.   If the soil-pipe is external
to the house, the defect is of less consequence, as
the foul gases find their  way  into the outer air.
Internal soil-pipes  are   generally  protected by
wooden casings, but this is not always so; and it
is even on record that an uncovered soil-pipe was
found in the  larder  of  a house  with  a  large
nail  hole  in  it.    The nail  had  been driven in
through the soft lead, in order to hang meat upon
it.  Galvanic action was  set up between the lead
and the iron of the nail, with the result that the
hole increased in  size,  and  the  nail  eventually
dropped out, thus  allowing foul air to escape into
the larder, and taint the meat, milk, fish, or other
food put there. 
DOMESTIC REFUSE              53
  The proper ventilation of the soil-pipe is another
important matter.  A soil-pipe closed at the upper
end, i. e. unventilated, is always  filled with  foul
air, which tends to eat into the leaden walls of the
pipe, and cause perforations or small holes.   Not
only this, but siphonage of the water-closet  traps
is far more likely to occur when the soil-pipe is
unventilated.  The mere emptying of a pail of slops
down a short hopper  closet connected with a soil-
pipe closed at the top, will cause the trap to suck
or siphon, and the water-seal to disappear, with
the result that foul air can then pass back into the
house.   In the case of two or more water-closets
attached to the same soil-pipe, the discharge of
one closet may cause the siphoning  of  the trap of
the  other, should the soil-pipe be unventilated.
The ventilation of the soil-pipe is also necessary to
give exit to foul air  in the drain with which  the
soil-pipe is connected.
  The ventilation of the soil-pipe should be effected
by carrying the pipe  full bore to the  top of  the
house, to a position remote from any windows or
chimneys, and there leaving its end freely open to
the air.  Particular care should be taken to  avoid
the  proximity  of  windows.  It is  not at  all  an
uncommon experience to find that the foul air from
a soil-pipe ventilator is  making its way  into the
house through an  open attic window.   It is  espe- 
54
THE ELEMENTS  OF HEALTH
cially for this reason that pipes taking rain-water
from  the  roof  should  not be allowed to act as
ventilators to the  soil-pipes, for the ends of these
pipes  are  often in close proximity to dormer win-
dows.  Points at which  defects in  soil-pipes are
very frequently found are :—the joint between the
foot of the soil-pipe  and the drain,  and the joint
between the china trap of the water-closet and the
branch of the lead soil-pipe.
  Cast-iron pipes are cheaper  than lead, and are
in consequence very largely  used  as soil-pipes.
Their disadvantages are that they are not so smooth
as lead on the surface, and that the joints, where
the different lengths of  iron  pipe  are connected
together, are not nearly so secure as the  soldered
wiped joints on lead pipes.    In   addition, lead
T pieces, as they are called, must be used to receive
the branches from  the water-closets;  and  the
joints between lead and iron pipes are very seldom
secure and sound.
  Anti-siphonage Pipes are now rather extensively
employed to obviate any risk of sucking or siphon-
age of the water-closet traps.   They are  made of
lead—two inches in  diameter being the usual size
of the pipe,—and after being connected with the
soil-pipe branches near the water closet traps, they
are taken through the outer wall, and carried up to
a place remote from windows,  or to  be connected 
DOMESTIC REFUSE
55
to the soil-pipe ventilator above the branch from
the highest closet.
  They are certainly not required in all cases, but
are found  of  especial value where the soil-pipe
branches are  long,  as  it is in these cases that
siphonage is most apt to occur.  They also serve
to ventilate these long branches, which otherwise
would become reservoirs of foul air.
  House-drains.—House-drains  are  the   under-
ground pipes  conveying the  sewage and waste
waters away from any premises  (domestic) to a
sewer  or  cesspool.   Being hidden from view,
underground drains  are  more often  defectively
constructed, i. e. " scamped," than any other class
of sanitary appliance.
   The following are  some of the chief  rules which
should be observed in the construction and laying
of  drains:— (1)  Wherever possible  the drain
should be laid  outside the house, and not in the
ground beneath it.   (2)  The drain should be laid
with a proper and even fall throughout its whole
length, the usual gradient being a fall of from 1
in 20 to  1  in 60 for houses of average size.   (3)
The drain should be laid on a bed of concrete for
its whole length.   (4) Glazed stoneware socketted
pipes should be used, the joints between the pipes
being  made  of Portland cement.  (5) For small
houses 4-inch  pipes  should be  used, for  larger 
56
THE ELEMENTS OF HEALTH
houses 6-inch pipes may be necessary,  but it is
very seldom  that  pipes 9 inches in diameter are
required.   (6) At a point near the sewer or cess-
pool a siphon disconnecting trap, with  fresh air
inlet, should  be fixed, to break  the  direct con-
nection between the house  drain  and the sewer,
and also to provide for  the entrance of fresh air
into the  house drain.  (7) The  upper  end of the
house drain should be ventilated by a pipe carried
full  bore up  to the ridge  of the  roof,  this pipe
being  not  less than  4 inches  in  diameter, and
having as  few bends and angles in it as can  be
attained.   The soil-pipe and soil-pipe ventilator
are usually made to serve this purpose.   (8) The
main drain and all its branches should be laid in
straight lines; where the main drain changes  its
direction, or  where branch  drains join  the main
drain,  inspection  chambers should be  fixed,  so
that each straight  length of main or branch drain
may be under control.   (9) Inspection  and dis-
connection chambers should not be placed  inside
the house, but in yards, areas, or other open  spaces
adjoining the house.   They should be covered by
" air-tight  " iron manhole covers.
  The most  serious  defects in house-drains are
those that permit sewage to percolate into the soil
beneath  or  around a  dwelling.   Defects  which
allow foul  air to escape into the  house  are little 
DOMESTIC REFUSE              57
less serious.  Houses in  which such defects  exist
are notoriously unhealthy to their inmates.  The
evil  effects of  living in  a damp  and  vitiated
atmosphere are sure to manifest themselves sooner
or later.
  Defective  drains may be  first indicated  by
illness amongst the occupants  of the house, but
perhaps it is more common, in the first instance, for
the defects to become manifest through the agency
of disagreeable odours.  These may not be notice-
able at all times or seasons, nor in every room of
the house; but at certain times, and in certain
spots in the house, it is probable  that foul smells
will be perceived.  It is certainly the fact that
during, or immediately preceding rain, the  smell
of drains  is often most  distinct; and this would
appear to be due to the  lessening pressure of  the
atmosphere accompanying or  preceding rainfall,
as indicated by the falling barometer.   In  cases
where the house drain is in direct connection with
the sewer, there being no intercepting or discon-
necting trap, the direction of the wind may have
some  relation to the occurrence of bad smells in a
house—certain winds  causing a strong current of
air in the  sewer, which passes into the house  drain
and, through defects in it, into the house, carrying
foul-smelling gases with  it.
  It will be as  well to point out that bad  smells in 
58
THE ELEMENTS OF HEALTH
a house  are  not always  due to  drains.  Slight
escapes of imperfectly  purified coal gas, owing to
leaky gas-pipes or gas burners; dead and rotting
mice or rats under the floor boards; wooden joists
and woodwork rotting from damp and deficient
supply of  air;  disused  and uncleaned chimney
flues,  may all give rise  to the  odours characteristic
of decaying organic refuse, and may, therefore, be
mistaken for sewer or drain gases.
  Long-continued dampness  of floors or walls in
the basement of a house is often originated by a
defective drain beneath, from which sewage escapes
into the soil around, and thence  rises by capillary
attraction to  neighbouring  walls or  floors.  Of
course this  state of dampness may be due to  a
naturally water-logged condition  of  the soil on
which the house is built, and  not to any defects in
the drainage.
  The most effective tests for drains are the water
and the smoke tests.  These  are best carried out
by sanitary inspectors or other experts in drainage
matters,  but  every  householder can carry out  a
fairly searching test for himself with  oil of pep-
permint.
  Half an ounce of this oil and a large can of hot
water are carried to the  top of the house by an
assistant, and the oil followed by the hot water is
thrown down  the  highest water-closet, or if the 
DOMESTIC REFUSE
59
roof can be reached, down the open end of the soil-
pipe ventilator, which is then plugged with a cloth.
The assistant must remain outside  the  house, or
shut up in the water-closet, until the search for
leaks has ended, as his clothes will retain the smell
of peppermint for a very considerable time.  Pep-
permint being a very volatile substance,  its aroma
will be perceptible to the  sense  of smell in the
vicinity of  any  leaks in the  soil-pipe  or  drain,
especially if these pipes are fixed  within the walls
of the house.  Should the underground drain be at
a  considerable depth below the surface, defects,
even if they exist, may not always be discoverable
by the peppermint test; and in  some  cases  it
happens that rat-runs convey  the vapour of pep-
permint, after a certain lapse of time,  to consider-
able distances away from the exact spots at which
the leaks are to be  found.
   The presence  of  rats and rat-runs in  or near a
house is usually evidence of bad  drains, as these
animals—in towns at any rate—nearly always come
from the sewers.  Where there  is  an  old brick
drain, the rats displace a loosened brick, and burrow
in the ground in search of food, often finding their
way eventually into the house  larder.  Rats,  too,
sometimes force  a  passage  through a pipe drain
at a place where a hole has been made to clear an
obstruction which  has choked  the drain, and the 
60          THE ELEMENTS OF  HEALTH

hole has been  subsequently  "made good"  by a
piece of slate or tile loosely embedded in cement.
  Drain grenades, consisting of little closed glass
capsules containing oil of peppermint or a compo-
sition of assaf cetida and phosphorus, which explodes
on contact with water, giving rise to very pungent
and peculiar smelling gases, are now largely used
by sanitary  inspectors, a dozen or  so being carried
easily in a pocket-case.
  Waste-pipes.—These are the pipes which  carry
away the  dirty water from baths,  sinks, and lava-
tory wash-hand basins.   These pipes  should  in-
variably be  disconnected from the drains or soil-
pipes of the house.  This is  a rule to which no
exception  should  be  made.   By  disconnection is
meant that the waste-pipe  should  discharge by an
open end in the outer air, the water  discharged
being received into a trapped  gully, which is itself
in  connection  with the drain.   The  waste-pipe
should be trapped with a siphon trap immediately
beneath the bath, sink, or  wash-hand basin,  to
prevent the passage  of air from  outside through
the  dirty pipe into  the  interior of  the  house
(Fig. 12).
  During the winter months of the year, the cold
outside air  constantly tends  to be drawn  into a
warm, occupied house.  The warmer air inside the
house,  due  to  the burning of coal in fireplaces, 
                DOMESTIC REFUSE             61

the heat of gas burners and lamps, and the warm
bodies of the inmates, is lighter bulk for bulk than
                     Fig. 12.
DISCHARGING OVER GULLEY
the colder outer atmosphere.  The warm air rises
and escapes up chimney flues, its place being taken
by  the cold air outside, which finds its way  in
through  any and  every opening.  Consequently 
62         THE ELEMENTS OF HEALTH
untrapped  waste-pipes form  a very  convenient
means of access of cold air to the house.  But it is
not desirable that houses should be ventilated  by
means of pipes coated inside with grease and dirt
from the surface of the human body, or from  the
washings of  dirty plates,  dishes, and  household
utensils.  The dirty lining to these pipes ferments
and produces foul gases, which would be drawn
back into the house  with the  entering  current of
cold air.
  Sore throats and  even  diphtheria  have been
attributed to trapless waste-pipes, more especially
in the case  of bath-rooms adjacent to  bedrooms,
or of  baths  actually in the bedrooms,  with long
lengths of trapless, unventilated waste-pipes.
  Waste-pipes  should  be of  stout  lead, three
quarters  to  two inches in  diameter, according to
the size of the sink, basin, or bath.  The advantage
of a large waste-pipe is that the dirty water runs
rapidly away, leaving the bath, sink, or basin in a
cleanly condition, and the rapid flow of water helps
to flush the drain and keep it  clean.  The siphon
trap should be provided with  a screw cap at  the
bottom  of  the  bend, which  can be opened  to
remove grease or other accumulations, which tend
to choke it; and in most cases it is desirable that
a ventilating pipe should be taken  off the waste-
pipe just beyond the trap, and carried through the 
DOMESTIC REFUSE
63
nearest external wall, to  prevent siphonage of the
trap,  which is  very  apt  to occur in pipes of  this
small calibre.
  The waste-pipes on the ground  floor should be
made to discharge over  stoneware gully-traps in
the ground outside the house.  Those on the upper
storeys of the house (above the ground floor) should
discharge into the open head of a rain-water pipe,
or  cast-iron pipe, which  is itself disconnected at
its foot over a stoneware gully.
  During severe frosts  the  external  position of
waste-pipes and soil-pipes may give rise to trouble,
the water  in the pipes  freezing,  and the ice so
formed causing  an  obstruction.    Frosts of such
severity are not of  frequent occurrence; and the
tendency to freeze may generally  be counteracted
by  pouring hot water,  in which  common  salt is
dissolved,  down the pipes two or three times a
day.
  Kitchen and scullery  sinks on  the  upper floors
in  mansions and flats  should have their  waste-
pipes  connected directly with iron  or lead waste-
pipes outside the house, without open heads; but
these main waste-pipes  should be carried up full
bore to the roof for  ventilation, and should be dis-
connected on  the ground surface  below in the
usual manner over stoneware gullies.  These sinks
discharge very dirty water at a high temperature, 
64
THE ELEMENTS  OF HEALTH
and the steam escaping from the ordinary open
heads is found to be a nuisance; besides, the out-
side  pipes become lined with filth, and it is not
desirable that the upper ends of these dirty pipes
should be situated close to living or sleeping rooms,
as would probably be  the case in buildings occu-
pied as flats and mansions.
  Porcelain baths,though expensive, are preferable
to metal baths, which require to be boxed in with
woodwork.  The space within the  woodwork con-
tains a lead or zinc  safe-tray on the floor to catch
any  overflow  of water or  drippings from  leaky
valves, and is usually in a dirty condition  owing
to its  inacessibility.   There  is a great advantage
in having  every portion of a bath-room or water
closet  easily accessible to broom, duster, and soap
and water,  The overflow pipes of baths and lava-
tory wash-hand basins should also be easily access-
ible  for  cleansing,  instead of being, as they so
often are, " concealed." A standing waste outlet,
which also serves as an overflow, is now made by
some firms, which can  be unscrewed at the bottom,
and  lifts out, so as to be readily  cleansed before
being replaced (Fig. 13).
   Sinks  of glazed stoneware, or whiteware, are
preferable on the score of cleanliness to the old-
fashioned stone sinks with  rough surface, or to the
lead-lined wooden sinks which present avery ridged 
DOMESTIC REFUSE
65
and uneven surface after some years' use.  Glazed
ware sinks require care in use, as they are apt to
chip and to crack from rough usage.
                     Fig. 13.
                 Lavatory  with
           Lifting  standinc  Waste outlet
   The waste-pipes of slop sinks intended to receive
excreta, and of urinals, should be trapped and
ventilated like soil-pipes, and connected directly to
the drain in the same way as soil-pipes.   It is not
desirable to discharge urine and faeces  into open
gullies.
   Rain-water Pipes should always be disconnected
from the drains  by being made to discharge over
gullies.  If this is not done there may be risk  of
foul air escaping at the top  of the pipe beneath an
attic window, or  under an overhanging  eave  in
proximity to a bedroom window.   In addition, the
                                       5 
66
THE ELEMENTS OF HEALTH
joints between the different lengths of rain-wate
pipe are sometimes leaky, very  often not caulked
at all, so that foul air may escape through leaky or
                     Fig. 14.
                    dirt e  - - -• .  . • . _—■
              ^"//Jt'/////////*  . • • •• • •  •-'•'
                Rain-water  Pipe
                  discharcinc
            into  concealed Culley

open joints on the face of the wall at various points,
near windows or living-room ventilators. 
DOMESTIC REFUSE
67
  It may happen that on examination it will be
found that there is a concealed siphon trap (Fig. 14)
at the  foot of a rain-water pipe, and that there  is
not a  free  passage for drain  air when the  trap
liolds water.  But it is obvious that when rain  is
long absent, the  trapping water may have evapo-
rated; and besides, it is often found that these traps
are choked  with rust  which has fallen into them
from the interior of the iron rain-water pipes  with
which they are connected.  The traps being inac-
cessible, can neither have  the rust and rubbish
accumulations removed from them,  nor can  they
be replenished with water very easily in times  of
drought. It is the safest plan to cause all  rain-
water  pipes to discharge in  the open air over open
gullies.
   Gullies and Bell-traps.—Stoneware siphon gully
traps (Fig.  12) for carrying off yard and surface
water to the drain, and for  receiving house waste
waters, are far preferable to the old-fashioned bell-
traps.   The gulley holds  a considerable volume
of water, whilst the  bell-trap (Fig. 15) contains
only a relatively small quantity, which is quickly
evaporated.  In consequence  bell-traps are  often
found dry, and useless.  Inasmuch as there is con-
siderable obstruction to the flow of water through
them the " bell," which is removable, is often taken
off to  facilitate the passage of water.  With the 
68          THE ELEMENTS OF HEALTH
bell  part  detached, the bell-trap is no longer  a
trap, and presents an opening in direct aerial com-
munication with the drain.
                     Fig. 15.
Bell Trap  with  Cover removed
  Bell-traps  were formerly extensively employed
both inside and outside houses.  Inside, they were
placed over sink waste-pipes, and in the floors  of
kitchens  and  sculleries  to  carry away to the
drains the water used for washing the stone floors. 
DOMESTIC REFUSE
69
They  formed  the  only protection  against the
passage of foul drain air into the house, and being
often broken, and with the "bell" detached, were
at best of very little use in doing that for which
they were designed.  In the highly-heatedbasement
rooms of a house, there is, as before  explained, a
great tendency for the inward passage of currents
of cold air, to supply the place of the lighter heated
air, which escapes up the chimney flues.  There is
besides the  direct  "aspirating"  effect of  the
kitchen fire, which, removing large volumes of
heated air, causes strong draughts to set in towards
it.  These draughts and currents of air were often
"laid on" so  to  speak, from  the drains into the
basement, by  means of leaky drain-pipes  and of
bell-trapped  or  untrapped  openings  into  the
drains, within the kitchen itself or its adjoining
scullery.
  Bell-traps in yards, outside the house, for carry-
ing off surface water, have the same defects, but are
less objectionable than when inside houses, being
in the open air.
  Gullies  cannot be untrapped except by removal of
the water in them.  When they receive very dirty,
greasy, kitchen waste waters, they should be pro-
vided with an inlet below the iron grating, as the
collection  of grease, tea  leaves, and  filth  on the
grating, when the waste-pipe of the  scullery sink 
70
THE ELEMENTS OF HEALTH
delivers over it, is objectionable.  Gullies should
be occasionally cleaned out by hand, to remove the
silt which collects in them.
  Grease-traps  and   Flushing   Grease-gullies.—
The  waste water  from  kitchens contains very
usually a  considerable amount of grease  or  fat
from  the washings  of plates and  dishes.  This
grease is liquid in the waste water owing  to  the
high  temperature of  the latter;  but when dis-
charged into the drain  the hot water cools,  the
grease solidifies,  and forms a coating or  lining,
which not only decomposes in the drain, giving rise
to foul gases,  but also tends to  accumulate, and
eventually choke the pipes.  This  is especially
liable to  happen in large mansions, hotels, and
restaurants, where cooking operations are carried
on upon a large scale.
   The older form of grease-trap,  designed  to pre-
vent  grease from getting into the drain, is, however,
as  great or a greater nuisance than  the condition
of  things it is intended to  remedy.  The scullery
sink  is made to discharge into  a large receptacle
containing sufficient cold water to cool the enter-
ing hot water, and so cause solidification of the
fat, which rises to the  top of the  water, being
relatively  lighter than water.  The accumulation
 of fat continues  until the cover of the grease-trap
 is taken off, and the fat removed.  The disturbance 
DOMESTIC REFUSE
71
of a large collection  of putrid fat causes  a most
abominable odour, and the principle of conserving
putrefiable refuse in or about houses is,  as before
explained, radically unsound.
  In the flushing grease-gully, the grease in the sink
water is also cooled by contact with cold water, and
solidifies.   But the collection of grease  is broken
up  and carried away through the drains, two or
three times a day, by the rush of water from an
automatic siphon  flush-tank into  the grease-gully
(Fig. 16). These tanks are constructed to hold
from 10 to 100 or more gallons of water,  accord-
ing  to  circumstances, and the whole volume  is
discharged, as soon as the tank is full, by the siphon
arrangement inside the tank coming automatically
into action.  The rush  of so  large  a  volume  of
water through the grease-gully breaks the grease
up  into small  fragments, and  bears them along
through the entire length of drain to the outlet in
sewer or cesspool.  The drain at the same time is
flushed, and  the regular periodical flushing main-
tains the  drains in a cleanly condition.
  The Flushing and Cleansing  of Drains.—The
periodical flushing of drains is an important matter
in the health interests of the inhabitants, especially
where the gradient is not as good as it should  be.
Drains laid with little fall are very apt to  become
silted up with  filth.   An automatic  flush-tank 
72         THE ELEMENTS OF HEALTH
should be connected to a gully at the head  of a
drain with deficient  gradient, and the tank should
   Fig. 16.

•f/.'A '/MM//,;
    Flushinc Crease Culley
             with
Automatic  Siphon  Flush Tank
be occasionally  inspected to ensure  its  regular 
DOMESTIC REFUSE
73
action.  It is desirable once a year  or  so to plug
the lower end of the drain in the disconnecting
chamber, and to fill it  and all its branches with
water up  to  the highest attainable level.  In this
manner drains of modern construction are not only
flushed  thoroughly,  but also tested  for leaks;  a
fall in the level of the water, after the  filling has
ceased, indicating the presence of defects through
which water is leaking away into the ground.
  Inspection  and disconnection chambers should
be opened once a month and flushed with  a few
buckets of water, the iron covers being cleansed
and provided with fresh grease on the  rims to
render  them  air-tight  when  replaced.  Gullies
should be cleansed and the silt removed from them
at about the same intervals—once a month. 
74           THE  ELEMENTS OF  HEALTH
Fig. 17.
Sectional Diagram or  SANITARY  House




                Fig. 18.
Sectional Diacram or  INSANITARY House 
DOMESTIC  REFUSE
75
FlG. 17.—Sectional Diagram of Sanitary Souse.
  A.  Short hopper closet with siphon trap.
  B.  Three-gallon water-waste preventer with 1^-inch supply-pipe
to closet basin.
  C.  Two-inch lead  anti-siphonage pipe, carried from the trap of
the lower w.c. to the soil-pipe ventilator, above the branch from the
top w.c, which is also provided with an anti-siphonage pipe.
  D.  Four-inch lead soil-pipe ventilator, surmounted by open wire-
work dome.
  E.  Four-inch drawn lead soil-pipe with wiped soldered joints.
  F.  Connection of foot of  soil-pipe with 4-inch  drain  above
surface of ground.   A brass ferrule is soldered on to the lead pipe,
and the joint between the brass ferrule and stoneware socket is made
with  Portland cement.
  G-.  Inspection chamber receiving 4-inch  branches from soil-pipe
and gully H, and closed above by an iron air-tight cover.
  H. Stoneware siphon gully trap for carrying off surface water.
  J.  Six-inch drain of  glazed  stoneware  socketed tested  pipes,
with  Portland  cement joints,  laid in a straight line, at a regular
gradient, from inspection chamber Gr to disconnection chamber K.
  Note.—The  inspection and disconnection chambers  should be
built  on concrete, and the main and branch drains should be laid
on  beds of concrete at  least  6 inches thick.  The drain is  shown
passing under the house, as would be necessary in the case of a row
of town houses, where the sewer is in the road to the front of the
house.
  K.  Disconnecting chamber  with air-tight iron cover.
  L.  Disconnecting trap with  raking arm or clearing eye I/.
  M. Fresh air inlet to disconnecting chamber.
  N.  Stoneware  gully discharging into main drain in disconnect-
ing chamber.
  0.  Scullery sink with trapped waste-pipe connected to side inlet
of gully N.
  P.  Rain-water and waste-pipe discharging over gully N.
  Q.  Lavatory  basin  with  trapped  and  ventilated  waste-pipe
discharging into open head outside house.
  R.  Bath with  trapped and ventilated waste-pipe  discharging
into open head outside house. 
76
THE  ELEMENTS  OF HEALTH
   S. Rain-water pipe receiving water from roof.
   T. Main cistern of  house supplying all taps and water-waste
preventers.
   U. Overflow or warning pipe of cistern carried through roof to
discharge in the open air.

FlG. 18.—Sectional  Diagram of Insanitary  Souse.
   A. Pan-andccontainer-  loset with D-trap,  supplied with water
for flushing from house cistern overhead.
   B. House cistern  supplying pan  closet below by means of  a
service-box on which is a valve, connected with  the  handle of  the
closet by wires.  The standing waste or overflow pipe of the cistern
is  directly connected with the soil-pipe.
   C. Bath with waste-pipe directly connected to soil-pipe.
   D. Lavatory wash-hand basin with untrapped waste-pipe, dis-
charging on to roof of outbuilding.
   E. Internal lead soil-pipe.   In the larder a nail has been driven
into the pipe  to attach a joint of meat, as described in the text.
   F. Rain-water pipe from roof of outdoor water-closet, in direct
connection with the drain.
   G. Outdoor water-closet.
   H.  Scullery sink with  waste-pipe in direct connection  with
drain.
   I. Basement house cistern  with overflow pipe discharging over
sink below.
   J. Draw-off sink with untrapped waste-pipe discharging into
open head.
   K. Bell-trap for carrying off surface water  to drain.  This trap
is  supposed to be dry.
   L. Underground house-drain in direct connection with sewer (not
shown), and without any disconnecting trap.
   Note.—The arrows show the points at which  foul air  from  the
common sewer, after passing through the house-drain, gains access
to the  house.  This  foul air would not  pass  through  the pan
closet unless the D-trap was dry from siphonage of the water in itj
the arrows here may  be supposed to represent  foul air  escaping
from the D-trap and container. 
AIR AND  VENTILATION
77
                 CHAPTER III

              AIR AND VENTILATION
Composition of air—Fouling of the air by respiration—Fouling of
   the air by combustion—Fouling of the air by rotting organic
   refuse—Ventilation—Cubic space and floor  space — Intro-
   duction of fresh air into rooms—Exhaustion of fouled air—
   Practical examination of the ventilation of rooms—Measure-
   ment of cubic and floor space.
  Atmospheric air has a remarkably uniform com-
position at every part of the earth's  surface.  Air
is not a single gas, but is a mixture of two gases—
oxygen and  nitrogen.  Oxygen  forms  about one
fifth by volume of the air, and nitrogen constitutes
the remaining four fifths of any volume of air.
  Oxygen is the  active gas in  air—the gas which
supports  animal life and the combustion of fuel.
Nitrogen only  serves to dilute  the more  active
oxygen.  If the atmosphere consisted entirely  of
oxygen, animal life and the processes of combustion
would be carried  on at far too  great a rate, and
there would  be an  immense  waste  of energy.
Besides these two principal gases there  is another
called carbonic  acid, which is present to the extent 
78
the elements  of  health
 of four parts in every ten thousand volumes of air,
 even the very purest air containing approximately
 this quantity of carbonic acid.  Carbonic acid is a
 compound gas, a molecule consisting of one atom
 of carbon combined with two atoms of oxygen.
  The  exact  percentage composition of  air  by
 volume may be stated as follows :
      Oxygen  .    .  Symbol 0   .  20-96
      Nitrogen .         „   N   .  79-00
      Carbonic acid  .    „   C02 .  0004

                                     100-00
  In addition to  these gases the air is never abso-
 lutely dry, but contains a greater or less quantity
 of watery vapour; and there are present  organic    *
 and mineral matters, chiefly suspended in the air as
 dust, which are found more especially in the air of
 inhabited places.
  The atmosphere is  constantly being polluted in
 a great variety of ways all over the earth's surface.
 The respiration of men and animals, the exhalations
 from their bodies, the combustion of fuel, the various
 industries disengaging noxious gases or effluvia,
 and all the fermentative and decomposition changes
 to which organised matter is  liable, tend  to  pollute
 and vitiate the atmosphere.  But the balance is
restored  and purification is  accomplished by the
forces of nature, which are of immense power and 
AIR AND VENTILATION
79
of universal distribution  and application.   These
are :—The winds, which dilute and sweep away im-
purities, both gaseous and suspended, bringing pure
air in from  mountain, moor, or sea, to  supply the
place of that dislodged.  A second agency of great
value is the  rain, which in its fall from the clouds
washes  the  air,  carrying down to the earth dust
and vapours, to  become incorporated with  the soil
and rendered innocuous.  A third agency is that of
growing vegetation, the green leaves  of all plants
having  the  power, in the presence  of sunlight, of
absorbing carbonic acid gas, fixing the carbon to
form the woody  structure of the plant, and  liberat-
ing the oxygen, which is  thus restored  to  the
atmosphere  and  the balance preserved.
   The influence of sunlight in destroying fungi
and  bacteria, their  germs  and spores—in other
words, microbes  of all kinds—must not be lost sight
of. The sun's rays are powerful germicides.
   Traces of another gas are found in the air of all
parts of the earth's  surface, except in  the neigh-
bourhood of inhabited places.  This gas is called
ozone;  it is a modified form of oxygen, being even
more  active than that gas in  oxidising  organic
matters.  It is  believed  to be generally absent
from the air of towns and  cities.
   Except  as  regards  this  supposed  absence of
ozone, the air of towns does not differ very mate- 
80
THE ELEMENTS OF HEALTH
rially, as regards the principal gases, from the air
of the thinly peopled country districts.   There may
be a very slight deficiency of oxygen, or  a slight
increase of carbonic acid, but the differences from
pure  country air are very small.  There is, how-
ever, a vastly greater quantity of dust in the air
of towns, and much of this  dust is organic, con-
sisting of  organic  vapours, bacteria,  fungi  and
their spores.  The almost infinitesimal alteration
in the constituent gases exerts probably very little
influence on the health of town dwellers, but the
breathing of organic dust is  certainly injurious to
health, and is one of the causes of that excess o£
mortality of urban  over country districts which
the Registrar-General's statistics demonstrate.
  The pollution of  the  atmosphere is  especially
noticeable in the crowded courts and alleys of  our
large  cities,  in the  narrow winding  lanes and
streets, which are  enclosed on both sides by blocks
of lofty houses, and in all places which are excluded
from the purifying influences of sun and air.
  Wide and airy streets, sufficient open spaces at
the rear of houses, the limitation of the height of
houses according to  the width  of the street upon
which they front, the planting of trees and shrubs
in the wider thoroughfares, and the setting apart
of open  spaces as parks, gardens, and recreation
grounds, are all factors of first-rate  importance if 
AIR AND VENTILATION
81
the purity of the atmosphere in our great cities is
to be maintained.  It  is  certainly true that  a
proper standard of health cannot exist if no atten-
tion is paid to the enforcement of those municipal
regulations by which alone can nature's forces for
the purification of the atmosphere be allowed their
proper sway.  The effects  of  living in vitiated air
are especially marked in the case of children.  The
proper growth of  the body,  the attainment  of a
good physique  and  of  a sound  constitution, are
difficult  under such conditions, and the strength
and  stamina of the race deteriorate.
   Fouling  of the  Air  by Respiration.—An adult
man. in a position of rest  breathes at the rate of
about seventeen respirations  a minute.  At  each
act of respiration about thirty cubic inches of air
pass in  and out of  the lungs.   Maintaining his
posture  of  rest  for twenty-four hours, about 425
cubic feet of air will have  passed in and out of his
lungs  in this period.  This  quantity of air will
be contained in a room 10 feet long, 4£ feet wide,
and  10 .feet high.
  Expired air as it leaves the lungs is  found to
have lost about 4 per cent,  of the oxygen contained
in pure,  iinbreathed air,  whilst it has gained 4 per
cent, of   carbonic acid.    The nitrogen remains
unaltered in amount.   The  oxygen is  absorbed
from the air by the blood in  the capillary blood-
                                       6 
82         THE  ELEMENTS OF HEALTH
vessels  of the lungs, and the blood in exchange
gives up carbonic acid.   The oxygenation  of th**
blood is necessary in order that the oxygen may be
conveyed to every tissue of the body by the circu-
lation, and so enable every process of vital activity
to be properly performed; whilst the carbonic ac.d
is one of the waste materials consequent upon vital
activity, which must be removed from  the tissues
by the circulating blood, to be got rid of  in the
lungs,  and so  to escape finally into the general
atmosphere.
   The composition of expired  air is as follows :
       Oxygen   .     .    .17 percent.
       Nitrogen  .     .    .79    „
       Carbonic acid   .    .4    „
   The air escaping from the lungs is also at very
nearly the same temperature as that of  the human
body, viz. 98-4° Fahrenheit.   It is saturated with
watery  vapour, and  contains  besides  a certain
quantity of organic matters in the form  of vapour,
of solid minute particles of debris, and of bacterial
micro-organisms.   This organic  matter in the
breath very  rapidly putrefies, even  if  ii>  is not
actually  in  a putrid condition as  if  leaves the
mouth.   It is very readily absorbed by su£li  things
as clothing, curtains, carpets, rough wall-papers,
and  porous walls or hangings, and is  difficult to
dislodge from these substances even by  fvee venti- 
AIR AND VENTILATION
83
lation.  The stuffy, close, and  disagreeable smell
of a crowded or dirty room is  entirely due to the
organic exhalations from the lungs, skin, and dirty
clothes of the occupants, and it is to the presence-
of this  organic matter that must be ascribed the
injurious influence upon  health which the breath-
ing of air fouled by respiration undoubtedly pro-
duces.
  The necessity of ventilation—by which we mean
the proper supply of fresh air into enclosed places,
and the removal  of fouled air  out  of  them—is
evident, when we consider that if a man was shut
up  in a room of  the  dimensions above given,
namely, 10 feet long, 4£ feet wide, and 10 feet
high, containing 425 cubic feet of air, and if this
room was hermetically sealed up, so  that no air
could pass into it or escape  from  it,  the  man
would be found dead or dying at the end of twenty-
four hours, for he  would have passed the whole-
volume of air in the room through his lungs; and
long before this point was reached, the fouling of
the air by organic filth  would have caused blood-
poisoning, or, as it has been termed, " putrid fever,"'
which must have  a fatal termination unless the
patient is taken out into a pure atmosphere.  Such
at any rate was the cause of death amongst the
victims of the Black Hole of  Calcutta incident of
infamous  memory, and  probably in  such  other 
84
THE ELEMENTS OF HEALTH
 examples of death from overcrowding in confined
 spaces (prisons and ships) as are on record.
   Individuals  casually  subjected for an hour or
 two to an atmosphere fouled by a crowd of people,
 as  in  theatres, churches, drawing-room  entertain-
 ments, and at public meetings, often  experience
 headache,weariness,nausea, or fainting—symptoms
 which rapidly disappear upon removal to a better
 atmosphere.  Those who by force of circumstances
 are compelled to remain,often in cramped attitudes,
 for many hours  day after day indoors, in offices,
 shops, workrooms, and factories, and to breathe an
 air constantly polluted in perhaps a minor degree,
 but still distinctly recognisable as " stuffy " to the
 sense  of smell on first entering from  the  outer
 atmosphere, are liable to suffer in health, although
 the exact form which such disturbance of health
 assumes will  depend very much on the constitu-
 tional  peculiarities of the individual.
  In some people there  will be complaint of con-
 stant  weariness, headache, indigestion, and loss of
 appetite, followed by anaemia, or deficient nutrition
 of the blood, with its  train of  symptoms.   The
 lassitude leads in some to a craving for stimulants—
 alcohol or tea—and habits of excess in these direc-
 tions  often  originate in this manner.   People in
this lowered condition of health are more prone to
suffer  from  colds or catarrhs, from bronchitis, 
AIR AND VENTILATION
85
pneumonia, and acute lung attacks, than are those
more constantly in the open air.  This proneness
to inflammatory diseases of  the air-passages is
aggravated by a highly-heated  and over-dried
condition of the air in  the room  where the day is
passed, such as may result  from the burning of
gas, or the use of hot-water pipes or close stoves.
  Destructive lung diseases, included for the most
part under the term consumption or phthisis, are
far more common amongst those engaged in seden-
tary  indoor  occupations  than  amongst  those
leading essentially out-of-door lives. We know now
that these are "tubercular"  diseases, dependent
upon the presence in the tissues of the bacillus of
tubercle,  as first discovered  by Professor Koch,
the great  German  pathologist.  This bacillus is
contained in the breath and expectoration  from
the lungs of consumptive patients, and it is easy to
understand how it may be conveyed through the
air  from the  lungs  of  the  sick  to  the  lungs of
apparently  healthy  people, who  are,  however,
predisposed either constitutionally or by defective
hygienic  surroundings  to  fall  victims to this
dreaded complaint.  In saying this it must not be
supposed  that  phthisis is infectious  in the  same
sense as is scarlet fever or measles.  Facts disprove
any such conclusion, for it is a matter of general
agreement that phthisical people rarely, if  ever, 
86          THE ELEMENTS OF  HEALTH
prove ir fectious under  conditions of ample cubic
space and efficient ventilation, such as are to be
f-und  in  well-regulated  consumption hospitals.
But there is evidence to show the  contagiousness
of phthisis under conditions of overcrowding and
insufficient ventilation,  especially when conjoined
with excessive  dampness in  the air.  But even
here it need not be  assumed  that  the bacillus of
tubercle is  directly transferred  through the  air
from the lungs of  the sick to  be  implanted in  the
lungs of the healthy.  It is more probable that the
bacilli remain for a time in the dust and debris of
overcrowded, damp, and filthy houses, and in this
congenial soil acquire more virulent infective pro-
perties than they were in possession of at the time
of escaping from the lungs.
  Children suffer  from foul  air  as much,  if  not
more, than adults.  For the first six months or year
of life the state of the air in the nursery is perhaps
of less importance than the maintenance of warmth
and the giving of the proper food, but after this
period the breathing of pure air is an essential for
proper  growth  and  nourishment.   Living con-
stantly in over-heated stuffy rooms leads to anasmia,
rickets, and certain  " wasting" diseases, such as
scrofula in its various forms,  which is in reality a
form of tuberculosis.
  Fouling of Air  by  Combustion.—In  most  in- 
AIR AND VENTILATION
87
habited rooms there are chimney flues to carry off
the products of combustion from open coal fires to
the outer air, but such is not the  case as a rule
with the products of combustion of coal gas.   It is
quite the exception to meet with special flues pro-
vided for the purpose of carrying away the products
of combustion of gas burners used for lighting;  and
even in many instances open gas fires, gas cooking
stoves, and gas water  geysers  for baths are fixed
in houses without any  provision of flues.  Unedu-
cated men of the plumber class, and even some of
the manufacturers (or  their agents)  of these  very
appliances will assert  either that there are no in-
jurious gases given off in the combustion of coal
gas, or that, being invisible, they must necessarily
be harmless.
  Such is not the case, however,  as  the following
figures show :—One cubic foot of coal gas of average
quality,  on combustion, unites with from 1 to li-
eu bic feet of oxygen.  This  means  that all  the
oxygen of from 5 to 8  cubic feet  of  air is used up
in  the   combustion, and is  therefore withdrawn
from that  volume of air.  About 2 cubic feet of
carbonic acid gas result  from the  combustion of
1 cubic foot of coal gas;  and if the  combustion is
at all imperfect, as when the flame is smoky, small
quantities  of carbonic oxide  are also  given  off.
Nearly half a grain by weight of sulphurous acid is 
88          THE ELEMENTS OF HEALTH

also produced by the burning  of  1  cubic foot of
average coal gas.  An ordinary gas burner for
lighting a room burns from 3 to 5 cubic feet of gas
per hour.
  To take an illustrative example.   Suppose a room
10 feet long, 10 feet high, and 10 feet  wide, and
therefore containing 1000 cubic feet of space,  with
two gas burners in it burning each 4 cubic feet per
hour.  If the room is hermetically sealed, so  that
no fresh air can enter or foul air escape,  at the end
of one hour  the  oxygen of at least 40 cubic feet of
the air in  the room will have been destroyed, and
the oxygen remaining, instead of forming 20'96
per cent, by volume of the air, will only form 20*12
per cent.  At the same time  16 cubic feet of car-
bonic acid gas are added to the air of the room,
and the volume of this gas in the air at  the end of
one hour, instead of  being 0*04 per cent., becomes
1'64 per cent.  It is  thus  seen  to what extent the
air of such  a room is devitalised.  The air is not
absolutely poisonous from  deficiency of oxygen
and excess of carbonic  acid, but it would certainly
be injurious to  remain in such an atmosphere for
any length of time.
   Another example of even a worse state of affairs
may be given as possible  under certain conditions,
and believed, indeed, actually to have occurred.
   Take  the case of a bath-room  10  feet  long, 
AIR AND VENTILATION
89
 10 feet  high, and 5 feet wide, and  containing,
 therefore, 500 cubic feet of space.  Suppose the
 room to  have its door and window tightly closed,
 so as to reduce the communication with the outer
 air or with the air of the rest of the house to a very
 low limit.   An  "instantaneous water-heater,"
 which burns 30 cubic feet of gas per hour,  has
 been fixed to heat the  water of the bath, but no
 flue has been provided.   Now,  about half  an hour
 is the time required to obtain by means  of this
 apparatus a bath full of hot water at a temperature
 of 100° F.—a little over blood heat.  In this time
 (the bath room being kept tightly closed) there
 will be added to the air 30 cubic feet of carbonic
 acid gas, and the  oxygen  of 75 cubic  feet of air
 will have been consumed.   Carbonic acid will be
present in the air to the extent  of 6 per cent.,
instead of only 0'04 per cent., and the oxygen will
 be reduced from 20-96 per cent, to 17*91 per cent.
  Very much the same  effect  might be produced
by the use of an open gas fire burning 30  feet of
gas per hour, in a small unventilated room, without
any flue being provided to carry off the products
of combustion.
  The atmosphere of a room containing 6 per cent.
of carbonic  acid and only  18 per cent, of  oxygen
might, and probably  would,  produce fainting,
 cessation of the  heart's action, and death.  The 
90
THE ELEMENTS  OF HEALTH
fatal accidents which have occurred from the use
of bath-heaters without  flues are, in the light of
these figures, capable of  an easy explanation.
  Carbonic  oxide—the gas which is the result of
imperfect combustion—is not often found in deter-
minable quantities in the air of living rooms.  It
is an exceedingly poisonous  gas, less than 1 per
cent, of it in the air  causing a form of asphyxia
which rapidly proves fatal.  This gas results  from
the combustion of coke  with  a limited supply of
air;  and, as is well known,  asphyxiation  by the
burning  of  charcoal  in  pans  in small rooms is
largely resorted to on the Continent by suicidally
disposed persons to ensure an easy and  painless
death.  It is also the gas used in the lethal cham-
ber for dogs at Battersea, owing to this property
of destroying life with the minimum of suffering.
  If coke is used as a fuel for warming inhabited
rooms, care  should always be  taken that the  coke
fire has an abundant supply of air, and that all the
products of combustion pass up the  chimney flue.
  Coal gas  itself  contains about 6 per  cent, of
carbonic oxide, and the  poisonous effects  of  " gas
escapes" into houses are largely  due to this  very
deadly  component of illuminating gas.  Small
escapes of gas  into houses  from defective pipes
and  fittings, when  long  continued, seem  occa-
sionally to  produce relaxed  and  ulcerated sore 
AIR AND  VENTILATION
91
 throats amongst the occupants.  The irritants here
 are, no doubt, the sulphur compounds  (especially
 the  bisulphide of carbon, which has a very  dis-
 agreeable and  penetrating smell), and  which  are,
 or should be, largely removed in the process of
 purification which coal gas undergoes  before dis-
 tribution to the gas-holders.
  The sulphurous acid gas given off in coal  gas
 combustion  also tends to have an irritating effect
 on the throat, which is heightened by the dryness
 of the air produced by gas burning.  For although
 water vapour or steam is one of the products of
 combustion, yet the temperature of the air being
 raised by the heat of  the burning gas, the relative
 humidity is lessened, and a seusation of dryness
 results, which is irritating to the air-passages lead-
 ing to the lungs.
  The sulphurous acid gas is  the product of com-
 bustion of coal  and coal gas, which exerts  such
 destructive effects on vegetation, mortar, and some
 kinds  of building stones out of doors,  and which
 damages pictures,  frames,  book  coverings,  and
 gilded or metallic articles indoors.
  Lamps and candles are, perhaps, on the whole
 less  injurious than gas as  illuminants.  An ordi-
nary oil lamp burns about 150  grains of oil hourly,
 consuming the  oxygen of rather  more  than three
cubic feet of air, and  producing  just over half  a 
92
THE ELEMENTS  OF  HEALTH
cubic foot of carbonic acid in the hour.   A candle
burning 320 grains per  hour produces  rather  less
than  half a cubic foot  of carbonic acid  in  the
hour.   Both  lamps  and  candles  require more
attention  than gas-burners,  in  order  to  secure
perfect combustion and to prevent the burning
of the wicks  with a smoky flame, which  causes
the dissemination  of foul-smelling  and  injurious
gases in the apartment where they are in use.
  The town fog, by which is meant the fog of a
yellow, dense, and sulphurous character, is very
largely the  result  of the almost universal  use of
coal as a fuel.    In the late autumn and early
winter months,  owing  to  certain meteorological
conditions,  the  air  becomes supersaturated with
the vapour of water, which in  country districts
produces  a  white  mist of greater or less density.
In the air are suspended innumerable particles of
water  of inconceivably  small  dimensions,  which
in bulk produce the opacity characteristic of mists.
In smoky towns, however, the soot in the air, con-
sisting of fine particles of  carbon given off from
the chimneys—domestic and manufacturing—con-
denses on the water particles, and  each becomes
coated with a greasy, sooty  envelope.  Here  we
have, then, the thick, yellow fog, which shuts off
the light from the sky  and envelops every object
in a grimy,  sooty pall of moisture.  The choking 
AIR AND VENTILATION
93
 and  irritating  effect  upon  the  nose,  eyes, and
 throat is  due to the  sulphurous  acid with which
 the fog is charged, itself also the product of com-
 bustion of coal.
  In London of  late years  two kinds of fogs can
 be recognised.   The high fog, which  exists above
 the level  of the houses, and which causes a pro-
 found darkness  by cutting off the light of the
 sun ; and  the ground fog, which invades our streets
 and dwellings, and is by far the more disagreeable
 visitor.
  Fogs are seldom if ever possible when the air
 is in brisk movement, i. e. when there  is any wind
 (except at  sea,  and  on the sea-coast).  Conse-
 quently fogs prevail most in calm weather,  when
 the barometer is high, and the type of weather
 is termed  anti-cyclonic.
  There is  no cure for yellow  fogs, except the
 abolition  of bituminous   or smoky  coal  as  a
 common domestic fuel,  and the substitution of
 smokeless anthracite coal, coal gas, or  other means
 of heating which do not throw off daily into the
 air huge volumes of unconsumed  carbon.
  Fouling of Air by  Rotting Organic Refuse.—
Under this  heading we may consider the effects
upon  health of  what  is commonly called " sewer
gas."   As a matter of  fact there is no  special gas
in sewers to which the name sewer gas can bo 
94
THE ELEMENTS  OF  HEALTH
given.  The  air  of  sewers and  drains does not
differ very materially from the outer air, except
in the case of choked and obstructed  sewers and
drains containing stagnant and putrefying sewage.
In such cases the sewer or drain air may be loaded
with foul and injurious gases to such an extent as
to cause serious  and even fatal illness amongst
workmen  engaged in opening and cleansing the
sewer.
  Whilst deprecating the use of the word " sewer
gas," and recognising that the air of sewers does not
differ very much, as a rule, from ordinary  atmo-
spheric air,  we must still allow  that the  air of
even  well-constructed  and well-ventilated sewers
and drains is liable at times to contain substances
or gases which are distinctly inimical to health.
There is positive evidence as to the truth of  this
statement,  and no  amount of negative evidence
can  outweigh reliable   evidence  of  a  positive
character.  Our knowledge is at  present insuffi-
cient to enable us to say exactly what these gases
or substances are in every case—whether they are
living, organised germs or microbes, or alkaloidal
vapours of almost unknown chemical constitution.
  This, however, can be said, that the offensiveness
of the smell of sewer air must not be accepted aa
a criterion of the activity of the poisonous sub-
stance in it.  It may well be that sewer air which 
AIR AND VENTILATION
95
is little offensive is as dangerous as the  most foul-
smelling sample ;  and inasmuch as the attention
is  not  aroused  by  the  usual  disgusting and
nauseous  odour, it  is easily conceivable that the
danger  may be enhanced.  Nature's warning by
the sense of  smell  is generally reliable, but it
does not  always  follow  that the absence of dis-
tasteful odour is a sign of safety.
  It being granted that the breathing of air from
drains  or sewers  is  likely at  times   to  prove
injurious  to  the  health  of some, at least, of the
individuals exposed  to the  emanations, it follows
that every precaution should be  taken to prevent
the passage  of air  from drains  and sewers into
the atmosphere we breathe.  As the chapter on
" Refuse Disposal "  shows,  the object  of modern
sanitary arrangements  in houses is to make im-
possible, as far as may be, the escape of drain air
into the  house.  The ventilator for the exit of
foul air from the drains  is always carried to the
top of the house, away from windows.
  In the streets, however, of most towns we still
find ventilators for the sewers opening at the level
of the road, and on occasion pouring forth volumes
of bad-smelling air in the faces of  passers-by.  It
is true that in thia position the air from the sewers
escapes into the outer atmosphere, and not into the
interior of houses.   The danger, therefore,  of the 
96
THE ELEMENTS OF  HEALTH
 production  of injurious results is lessened by the
 possibility of the rapid dilution of noxious mat-
 ters by a copious supply  of fresh air.  All the
 same it  is  conceivable, and is  indeed probably
 the fact,  that  open  roadway ventilators  do at
 times and  upon  certain susceptible people exert
 an influence which originates ill-health or disease ;
 and it certainly  seems desirable that the same
 steps should be taken to protect the public from
 inhaling injurious  gases,  as are  taken by  the
 householder  to  protect himself  and  his family.
 Dust-carts and the vehicles that remove offal  and
 offensive  refuse  through  the  streets  are  now
 required  to have covers, or  to be  so constructed
 as to  prevent the escape of noxious effluvia to the
 annoyance  of the public, but little  or nothing is
 done to remedy the obnoxious open sewer venti-
 lators.
  It may be as  well  here to draw attention to
another matter  under  municipal control, which
 very probably affects injuriously the public health.
 It has become very much the custom of late years
to lay wood pavements in the most  frequented
thoroughfares of our large towns.  In a very short
time the surface layers of the wood become satu-
rated with organic matters from horse-droppings,
and this organic  filth putrefies in warm weather,
the gases of putrefaction passing into the general 
AIR AND VENTILATION
97
 atmosphere of  the streets.   The condition of the
 air of the main thoroughfares of  London in warm
 and dry weather, when the cleansing effect of water
 upon the wooden roadways is absent, is distinctly
 unwholesome—to use no stronger expression.  In
 many cases the great height of the houses abutting
 on these streets accentuates the evil by hindering
 the proper access of wind currents, and promoting
 stagnation of the atmosphere.
   Unless wood pavements can be regularly flushed
 with water, so as to  sweep away  the accumulated
 surface impurities, they are not sanitary, whatever
 other advantages they possess, and are far inferior
 to asphalte.
   The organic vapours given  off from brick-burn-
 ing, bone-manure works, fat-rendering, soap-boil-
 ing, and other  offensive  trades, are very often a
 source of nuisance and the subject of bitter com-
 plaint, but it is not always possible to prove that
 such emanations are injurious to health.  They, no
 doubt, at times  excite feelings of nausea and dis-
 gust, and tend to embitter the existence of resi-
 dents in the immediate locality.   Fortunately the
 Public Health Act enables local sanitary authori-
 ties to deal with such nuisances, and the law can
 always be put in operation in flagrant cases.
  The  object  of the  sanitary laws of the country
is to protect the  public from  nuisances of this
                                      7 
 98         THE ELEMENTS OF HEALTH

 character,  and it  is  the  duty  of  the  sanitary
 authority to enforce the law, so that  the private
 persons aggrieved  may not be put to the expense
 of procuring a remedy which is  for the protection
 of the public generally.
   The effects upon  the bodily health of breathing
 air mixed with putrefactive products are very much
 dependent  upon the individual, and his state of
 health for  the time being.   Many people, those
 perhaps  of robust constitution, in sound bodily
 health, are not adversely affected.   Even a short
 exposure in people less  happily constituted may
 produce sickness, headache, and diarrhoea.  Very
 severe forms of sore throat—ulcerated  or diphthe-
 ritic—may  result  from exposure to drain or sewer
 air. Typhoid fever is certainly occasionally spread
 by the air of drains and sewers which have received
 the evacuations of patients suffering  from this
 disease.  In some cases of prolonged exposure to
 drain emanations, such  as may occur in houses
 where the drains are defective, the symptoms pro-
 duced  are those of debility and anaemia, and the
 system appears to become  to  a certain extent
 habituated  to the poisonous matters.  It certainly
 seems  that  persons suffering  from wounds  are
liable to contract  erysipelas or blood-poisoning, if
living in an atmosphere contaminated with sewage
emanations;  and women  recently confined  are 
AIR AND VENTILATION
99
often the subject, under such deleterious surround-
ings, of forms of blood-poisoning which go by the
name of " puerperal fever " or " puerperal septi-
caemia." It has been convenient in this connection
to allude more especially to the effects of drain or
sewer air, but no doubt illnesses of a somewhat
similar character  may be originated by the emana-
tions arising from other sources in which organic
matters are being subjected to fermentation and
putrefaction.
                  Ventilation.
   The science of  ventilation is concerned  with the
supply  of fresh air to an  enclosed  or  inhabited
place,  and  the withdrawal  of used-up,  foul,  or
vitiated air from that place.
   In practice there are two main points to which
attention is  usually directed, namely,  (1)  the
amount of cubic space available for each individual
in  an  inhabited  room; and  (2) the quantity of
fresh air entering  the  room  from  outside  in a
certain period of  time.
   Cubic Space.—It is necessary that each individual
should have a certain amount of cubic or air space
around him, in order that he may  not have  to
breathe the expired air  of  his neighbours before
this has been properly  diluted with fresh  air.
People  who are very closely  crowded together in-
hale each other's breath, i. e.  the air which has just 
100
THE ELEMENTS  OF  HEALTH
left the lungs;  and in  addition they absorb  the
exhalations from each other's persons and clothes.
In densely packed halls and  assembly  rooms, the
audience are subjected to a slow process of respi-
ratory poisoning from the effects of the inhalations
of air loaded with organic matters.
  It is, therefore, essential to health that every in-
dividual in an inhabited room should have a certain
amount of air space available for himself, to draw
upon for his own air supply,  and also  to separate
him from his nearest neighbour.   Now  the cubic
space of any room is  obtained by  multiplying to-
gether the three dimensions of the length, breadth,
and height of the room; and  inasmuch as the
rooms of ordinary-dwelling houses are  pretty  well
proportioned as to their  dimensions in accordance
with their size, the cubic space so obtained need
only be divided by the number of occupants  in
the room, in order to get the air space or cubic
space per head.
   It will be apparent from what has been said  of
the primary object of a sufficiency of cubic space
per individual, that very great height in a room  is
of  less  use than a sufficiency of floor area (length
of room multiplied by its width) ; for it is the re-
lative size of the floor area that serves  to separate
the individuals in a room from each other ; and the
height  of the  room  above 5 or  h\   feet  only 
AIR AND VENTILATION
101
provides air space above the heads of  the people,
when in an erect attitude.  As a matter of fact
any  height of a dwelling or sleeping room  above
12  feet is comparatively worthless as air  space
to the individuals in that room;  and  contrary to
the popular notion, very lofty rooms are not more
airy and healthy than rooms of average height, say
10 to 12 feet.
  It is true that the gaseous  products (carbonic
acid) of respiration may diffuse into the air in the
upper part of a  lofty room; but the  organic
matters do not so diffuse, and tend to  accumulate
in the lower portions of the apartment; and it is
to these matters that are now  ascribed the dele-
terious effects of breathing air vitiated by respi-
ration.   It has been said that the whole or a great
portion of the inhabitants of our globe could find
standing-room on the Isle  of Wight;  but if they
were so congregated together they would undoubt-
edly perish, even with the  open sky above them,
for the close crowding would cause a condition of
atmosphere in the lower strata  available as an air
supply, which could not support life.
  In public buildings, such as churches,  chapels,
concert rooms, assembly halls,  &c, a much greater
height is given to the fabric than 12 feet, and
the space above this  height is no doubt useful as
forming a reserve  of air.  But  still in such places 
102
THE ELEMENTS OF HEALTH
the air is considerably  more  vitiated near the
floor than it is in the neighbourhood of the ceiling ;
and if it were not that the congregation or audience
does not  stay in the  building for a prolonged
period, it is probable that the effects of crowding
would manifest themselves even more than they do.
  Before giving any figures as to the amount  of
floor space and cubic space desirable in  the case
of ordinary living or sleeping rooms for the  main-
tenance of a proper standard of health, it may  be
useful to give the figures adopted  under various
conditions in  State or municipally regulated estab-
lishments, in public  schools, and in hospitals.
  English Education Department for Public Ele-
mentary Schools:—Floor space,  10 square  feet;
cubic space, 100 cubic feet per scholar.
  Metropolitan Common  Lodging-Houses  under
the control of the London County Council :—Floor
space, 30 square  feet;  cubic space, 240 cubic feet
for each adult over twelve years.
  Metropolitan Sanitary Authorities' regulations
for  dwelling  rooms  :—Cubic space, 300 cubic feet
per adult; 150 cubic  feet for each child under
twelve years.
  Factories and  Workshops   under the Public
Health  (London)  Act,  1891:—250  cubic feet per
adult in the daytime ; 400 cubic feet after 8 p.m.
Two gas burners to  count as one adult. 
AIR AND VENTILATION
103
  Workhouse Dormitories under the Poor Law :—
300 cubic feet for each adult.
  Military Barracks :—600 cubic feet per head.
  Prison cells in H.M.'s Prisons :—800 cubic feet
(with artificial ventilation).
  Public Schools (average), in dormitories with-
out cubicles:—600  to  700 cubic feet per scholar,
and  50 to 60 square feet  of floor space.  With
cubicles a larger amount should be allowed, as the
partitions obstruct free ventilation.
  General Hospitals with cross-ventilated wards :
—100 square feet of floor space,  1200 cubic feet
of air space.
  Infectious Disease Hospitals :—150 square feet
of floor space, 2000 cubic feet of air space.
  It is certainly true that the  amount of  air and
floor space allowed in public elementary schools, in
common lodging-houses, and in the houses of the
poor  is very insufficient, and  is not adequate to
maintain a  good  standard  of  health.   But it is,
perhaps, impossible at the present time, having
regard to the social  condition and wage-earning
power of the labouring classes, to insist upon any
larger amounts.
  The lowest amounts really compatible,  in ordi-
nary living  and sleeping  rooms, with health and
comfort, are 80 square feet of floor space, and 800
cubic feet of air space per adult; and  half these 
104         THE ELEMENTS OF HEALTH

quantities for young children, say under ten years
of age.
  If a room is badly lighted and ventilated—for
instance, without a chimney flue, or with a window
opening into an enclosed courtyard and facing a
blank wall at  a distance of a few  feet, or with a
skylight instead of a window—the amounts of floor
and air space should be increased.   These condi-
tions are often found in attic and basement rooms
(cellar dwellings); and it often becomes a question
whether such rooms are fit  to be lived in at all.
The Public Health (London) Act lays down very
stringent regulations as regard the height of rooms
in basements (the floors of  which  are more  than
3 feet below the surface of the adjoining street),
the size of windows, and the width of open  area,
which must be complied with if  such cellar dwell-
ings are used as sleeping places.
   Introduction of Fresh Air into Rooms.—The two
chief natural  forces which effect the introduction
of fresh air from outside houses into their interiors
are (1) winds and (2) the differences in weight of
contiguous masses of air of unequal temperature.
   Winds  produce  an effect in  proportion to the
velocity with which the wind is blowing.   As the
air is but very seldom completely stagnant in this
climate, the opening  of a window  is sufficient to
entirely disperse the air in a room  and to replace 
AIR and ventilation
105
it  with fresh  air;  and the effect  is heightened
enormously if windows on opposite sides of a room,
or a window and door, are opened  and kept open
for a short time, so that  the air may blow through.
In a few minutes the air of  the room is  freshened
and  sweetened,  and rendered again fit for  occu-
pancy.
  Methods  such as this  are  most valuable  for
thoroughly ventilating unoccupied living and bed-
rooms, schoolrooms during hours of play, churches
between Divine service, &c.   In  summer  it is
usually possible to sit in a room with open windows,
and if the draught can be borne, any other means
of ventilation are not required.
  In  winter, however,  we cannot  sit with open
windows and  doors,  and then reliance  must be
placed upon the ventilation effected by contiguous
volumes of air at unequal temperatures.  In  the
interior of the house, owing  to fires, gas lights,
lamps, and  the  warm bodies  of the inmates,  the
air becomes heated.  Heated  air  is lighter than
the  same volume  of cold  air, and consequently
rises and  tends  to escape out  of the room, whilst
the colder air from outside the house  pushes in
through every available opening to  take its place.
  The English  system  of open  coal fires  very
materially aids  the ventilation.   The heated air
escapes up the chimney flue with the products of 
106
THE ELEMENTS OF  HEALTH
combustion of the coal; and the fire itself not only
creates a draught  of  air towards it to supply the
oxygen necessary  for combustion, but also  keeps
the chimney flue hot, and so keeps up the tempera-
ture of the air  escaping through  it until such air
emerges at the  chimney top.  If the chimney flue
were not so heated, the hot air escaping up it would
gradually cool down, imparting its heat to the cold
bricks of the chimney, and at  length would become
as cold, or nearly  as cold, as  the  outside air, with
the result that  the current  would slow down or
cease  altogether, and the  ventilation be brought to
a standstill.
  The English  open coal fireplace with a good fire
burning in it is, therefore, an excellent ventilator.
It not only provides  a fine  exit for heated and
vitiated air,  but it draws air into the room to
supply the place of that which has escaped; and
it only remains  to provide that the air which so
enters shall  come from unimpeachable  sources
outside the  house, and  when it  enters the room
shall be so distributed as to mix evenly and gently
with the air  already  there, so as to  freshen and
renovate the apartment without the production of
cold and draughts.
  It is in this  last direction, however, that we so
often  meet  with failure.  It will  sometimes  be
found that the air to supply the fire, and renew 
AIR AND VENTILATION
107
the  atmosphere  of  the occupied living  room, is
entering from  the passage or staircase;  and, on
being further investigated, is ultimately traced to
the kitchen in the basement, from which it brings
the smell of cooking for delivery into the upstairs
apartments.  Occasionally the air is found to be
proceeding from a water-closet on a landing, the
window of which has been  left open the better to
ventilate the water-closet, but in reality to  venti-
late the house through the water-closet.
  The cold air which  enters from  the  passage
passes underneath the  loosely-hung door of the
living room, and travels straight  to  the  fire.   It
produces little effect in changing the  air of the
room for this reason, but it has considerable power
to chill the feet of the occupants of the room; and,
as very many people are aware from experience, to
sit around the fire is warming  to the face and body
but  chilling to the feet, which  are in the line of
direct draught from door to fireplace.
  If the air enters—as very often it does—at the
sides or between the sashes of the window, it tends
to fall like a cascade upon the heads of the persons
sitting in the room.  For,  being  colder than the
air of the room, it at once sinks when brought into
contact  with  the warm  air,  and thence travels
along the floor by direct route to  the blazing fire.
In a room of this description it is often exceedingly 
108         THE ELEMENTS OF HEALTH
difficult in chilly weather to find a place to sit
where one is  not either exposed  to a cold current

                     Fig. 19.
Badly Ventilated Room
upon the unprotected head, or to a chilling draught
upon the sensitive feet (Fig. 19).
  It is  evident, then, that something should  be 
AIR AND VENTILATION
109
done to  direct the incoming  air so that it may
thoroughly mix with the air already present in the
room, and be distributed uniformly throughout the
room in such a way as to ensure the proper reno-
vation and sweetening of the atmosphere, without
the production of draughts and chills.
  To  a great extent this desirable result can be
attained  if the entering air  is  given  an upward
direction as it flows into the room.   After leaving
the ventilator the  upward  direction is continued,
and the cold air mixes with the heated  air near the
ceiling of the room.   It here becomes warmed to a
certain  extent, and  pretty thoroughly distributed
throughout the apartment.  When it sinks towards
the floor it is—or  should be—no longer it so low
a temperature as to create a sensation of cold upon
the heads of the  occupants; and  is finally drawn
away as vitiated air up the chimney flue.
  It is important that the fresh  air should  be
allowed to enter the room above the heads of the
occupants, and therefore the height of  the inlet
above the floor should be about  six  feet.   It  is
equally desirable that the  inlet should  be capable
of being diminished in size or  closed altogether,
for when the outside air is very cold, or the wind
is blowing directly into it, the amount  of cold  air
entering may create draughts and lower the tem-
perature of the room to an  undesirable  extent. 
110         THE ELEMENTS  OF  HEALTH

  Some simple and effectual methods of ventilating
a room in this way are (Fig. 20)—

                     Fig. 20.
Room fitted with , various Ventilators
  (1) Hinckes-Bird's plan, in which a solid block
of wood is placed under the entire length of the
lower sash frame of  a window, and thereby raises
the top rail of the lower sash above the bottom rail
of the upper sash.    Air  passes into  the room 
AIR AND VENTILATION
111
between the two sash frames in the middle of the
window,  and above  the heads of people sitting
down in the room, and takes an upward direction
towards the ceiling.
  (2) The top sash of the window may be a little
lowered,  and  a Venetian blind let down over the
opening,  with the laths  so  arranged  as  to direct
the entering current of air upwards.
  (3) Louvred panes may be employed to replace
one of the upper squares of glass in the window;
or an arrangement may be adopted for allowing a
square of glass in the upper portion of the window
to fall inwards upon its lower border, at  the same
time providing side checks, and a cord by which
the ventilator may be closed.
  .(4) Wall-inlet  ventilators  may be employed.
Tobin's tube is now largely used.   It consists of a
vertical  tube  standing  up to a height  of about
5£ or 6 feet in the room, and connected underneath
the floor  boards with an opening through the outer
wall to the open air.   The upward direction given
to the entering air causes it to travel to the ceiling
of a  moderately  sized room  before it begins to
descend.   The  opening  under the floor should be
capable of being closed by  a  valve when desired;
and when the tube is fixed on an inner wall of a
room, and a shaft is carried under the floor from
the external to  the internal wall, there should be 
112
THE ELEMENTS OF  HEALTH
some means of  access to this horizontal  shaft for
removing soot and dirt which may collect in it.
  (5) The Sheringham valve is, perhaps,  less com-
monly employed than the Tobin tube.  Air passes
through  an opening in the wall near the ceiling,
and then meets a valved plate placed at an acute
angle, so that  the air  may be directed  upwards.
The plate is hinged at its lower border, and is pro-
vided with  side checks, and  can be opened  or
closed by means of a balanced weight.
  By such means as these, or by the  use  of similar
contrivances, it is usually  possible to arrange for
the satisfactory ventilation of occupied rooms.  Of
the two evils—stuffiness and draughts—most people
will choose the  former, and perhaps with reason;
for sedentary living, heated rooms, and little exer-
cise  out  of doors render the system  extremely
liable to chills, which  may develop very  rapidly
into  catarrhs,  bronchitis,  rheumatism,  or  other
complaints commonly attributed to " taking cold."
It is certainly the fact that for at least six months
of the year ventilation  is  far  more agreeable and
easy to carry out if the entering air  is first of  all
warmed  up to  a temperature of 65° F.,  but  in
the great majority of  houses no means exist for
securing so desirable a result.
  Exhaustion of Fouled Air.-—As already said, the
chimney flue serves,  on the whole, very efficiently 
AIR AND VENTILATION
113
as a means of exit for used air, when there is a
fire burning in the grate.   The time of year when
the family living room is most stuffy is the season—
spring or autumn—when it is too cold to  have the
window  open, but not cold  enough  for  a fire.
Without the fire, the chimney flue is but of little
use, unless it happens to run up in the same stack
with the kitchen flue, so that the air in it is main-
tained in a warm condition.
  If there is gas burned in a room, it is generally
desirable to have an additional exit for hot, fouled
air  near  the  ceiling.  Perhaps  the  best  is  the
chimney-breast ventilator (Fig. 20), which is  an
opening into the chimney flue  near the ceiling, and
is protected by little mica flap valves against the
issue of smoke into the room. The mica valves open
inwards towards the flue, but  are pressed  against
their  seatings when the pressure  in the chimney
flue exceeds that in the room.  These valves very
often  make  a disagreeable clicking noise,  and  do
not always, after a time, prevent the regurgitation
of smoke; but they  are  certainly useful in  pro-
viding an exit for the heated, vitiated air which
collects near the ceiling of a gas-lighted room.
  Smoky Chimneys are not only a serious nuisance,
but they sometimes render a  room uninhabitable
in cold weather.  One cause of a smoky chimney
is insufficient supply of air to the room from which
                                      8 
114
THE ELEMENTS OF HEALTH
the chimney leads.  To feed the fire  with air, a
puff descends the chimney carrying smoke with it
into the room; the  amount of air  available from
other  sources being insufficient to support com-
bustion, and enable the fire to burn. The remedy
for such a state of  things is evidently to provide
an opening to the outer atmosphere, through which
the fire may be fed  with  the amount of air neces-
sary.
  More often, perhaps, the  cause  of  the  smoky
chimney is that the  chimney top is overshadowed
by higher  buildings  (Fig. 21).  The wind striking
these obliquely, rebounds upon the chimney top,
and drives air and smoke back into the room.  This
is  especially likely to happen in stormy, squally
weather.  Here the remedy is to carry the chimney
top, if possible, to  above the level of the over-
shadowing buildings—a feat, however, which is not
always capable of execution.   A cowl will some-
times  be  of service under  these  circumstances,
because it  prevents rain getting into the  chimney,
and may mitigate the down-draught.  Too much
reliance should not be placed  upon  cowls, as  they
very often fail to effect much improvement.  Some-
times  good may result from narrowing the chimney
throat, and  so lessening the volume of cold air
escaping up the chimney, which tends to decrease
the up-draught; but perhaps the sweeping of the 
AIR AND  VENTIi. TION
115
Fig. 21.
Wind  strikinc  down  Chimney
    FROM HICHER  BuiLDINC 
116
THE ELEMENTS  OF HEALTH
chimney to clear it of soot is, as often  as  not, the
true remedy.
  There is considerable advantage in  having the
chimney flue  carried up in an inner wall, and not
in an  outer wall.  In the inner wall the  flue not
only preserves its  heat, which  is essential for its
prober working as an exit ventilator, but  the heat
.vhich does escape goes to warm the house, and is
not lost as it would be on an outer wall.
  Exit  Ventilators  for carrying  off gas-products
separately from  the chimney flue should always be
covered by cowls  to prevent the entrance of rain
into them.   This  class of exit  ventilators  often
prove troublesome, owing to their becoming inlets
for the entrance of cold air upon the heads of the
occupants of  the room, and not serving the purpose
for which they were designed.  It will often happen
that when a strong fire is burning  in a room, the
rush  of air  up  the chimney  causes every  other
opening into the room to become an inlet, so that
exit ventilators  in a room usually occupied with a
fire burning must be recommended with caution.
  It  is not possible to enter upon the  question
of ventilating large buildings, such as hospitals,
theatres,  halls,  and concert  rooms by means  of
artificial methods of ventilation; but  it may be
said  generally that it is often useless to trust  to
natural ventilation in such cases, and that a proper 
AIR AND VENTILATION
117
 air supply in sufficient quantify and at a suitable
 temperature is only possible by artificial methods,
 such as the use of fans driven by  power  for pro-
 pelling air  into  the buildings, or fov extracting
 the vitiated air.  The entering air in these cases
 can be readily warmed by allowing it to pass over
 coils of hot-water or steam pipes.
   Practical  Examination of  the  Ventilation  of
 Rooms.—The simplest test of the state of ventila-
 tion of an occupied room is afforded by the sense
 of smell.  On  entering directly from the outer air
 into a room, the nose is able to differentiate with
 considerable accuracy varying  degrees of  stuffi-
 ness.   A  feeling  of repulsion is  experienced,
 which, however, soon passes off if  the stay in the
 vitiated atmosphere is prolonged.   If the ventila-
 tion of the room is effectual, no sense of stuffiness
 is experienced  on entering from  the outer air.
 It is   certainly extraordinary  how sensitive the
 olfactory organs are to foul air,  and how  abso-
 lutely  they may be relied  on to give true indica-
 tions ;  but it is only right to mention that  above
 a certain limit of impurity the nose is  unable  to
 discriminate greater degrees of pollution.  As a
matter of fact, however, these higher degrees  of
impurity are not very often reached in inhabited
rooms.  The essential point to remember is that
the sense  of  smell  can  only be trusted  when 
118
THE ELEMENTS OF  HEALTH
 entrance from the  outer air has immediately pre-
 ceded the testing,  and that the length  of stay in
 the  open air should have  lasted  at  least  ten
 minutes.
   Measurement of Cubic and Floor Space.—Where
 the room is  of regular outline, the  measurements
 are effected without difficulty.   To obtain the floor
 space, the length and breadth  of the room must
 be multiplied  together;  and to know  the  cubic
 space,  this  result  must be  multiplied  by  the
 height.
   Difficulty is  likely to be experienced  where the
 room is  of irregular shape, with a portion  of  the
 ceiling raised  above the rest.  In  these cases it
 will usually be found  the simplest  rule to divide
 the floor area  up into  a number of  simpler forms,
 multiplying  each by its  appropriate height, and
 finally adding  together the totals  so obtained.
   Example.—Find the cubic contents of a room
 of the shape given in sketch (Fig. 22), having a semi-
 circular bay 10 feet in diameter ?  The  height of
 the room over the bay is  12 feet,  and over  the
-remaining portion 10 feet.
   *h* The floor area of the room may be divided
 into three portions, viz. :  (1) A rectangular space,
 A D E  B, whose superficial area is 15  x 10 feet
 = 150  square feet.  (2) A triangular portion,
 ABC, whose superficial area is  5  x 5 feet = 25 
AIR AND VENTILATION
119
square feet (the  area of the  triangle  ABC is
equal to the base A  C [5 feet]  x half the height
Fig. 22.
■^
A B  [5 feet] ).  (3)  A  semicircle, D F E, whose
     n  ■ i        •   102x 0*7854    QOO(7
superficial area   is---------  = 39*27  square 
120         THE ELEMENTS  OF  HEALTH

feet.  (The  area of a  circle = the square of the
diameter multiplied by 0*7854.)
  The cubic contents of  the semicircular bay are
39*72 x 12 = 471*24  cubic feet;  and the cubic
contents  of  the  remainder  of  the  room  are
(150 +  25)  x 10 = 1750 cubic  feet.  The cubic
contents of the entire room are, therefore, 1750 -f
471*24 = 2221*24 cubic feet. 
WARMING
121
                 CHAPTER IV

                    WARMING
Open fireplaces—Coal and pollution of the air by smoke—Gas
    fires—Ventilating fireplaces—Ventilating and close stoves—
    Hot-water pipes.
   In all cold climates  houses  must be provided
with some means of producing  artificial warmth,
as it is neither healthy nor comfortable for people
to be at rest for any long period in cold rooms.
A suitable  temperature for day rooms  is  from
60°  to 65° Fahrenheit,  whilst  bedrooms  may be
occupied  at  a  considerably  lower temperature
without injury to health, and, indeed, with advan-
tage to soundly-constituted people.
   In the very great majority of the  houses in this
country, open fireplaces for the burning of coal
are fixed in  the living  and bed rooms  to supply
the heat  necessary to maintain an agreeable tem-
perature.   These  open fireplaces  heat   objects
around them  by radiation, by which is meant the
passage of air in straight lines from  hot bodies
to cold  ones, the  rays  of heat passing through 
122
THE ELEMENTS OF HEALTH
the air, but without warming it.  Such  sources of
heat are extremely wasteful, as, on the average,
more than half the heat given out by the burning
coal escapes  up the chimney flue;  but the open
fireplace is eminently a healthy appliance, because
it acts as a ventilator, causing a current of  heated
air to pass away by the chimney, and so inducing
the entry of cold, fresh air to supply the place of
that withdrawn.
  Open coal  fires  are  perhaps, on the whole, the
most suitable form of heating appliance  for houses
in this country, where we  habitually enjoy,  for
the most part, a mild  and equable winter;  but in
times of frost and great cold their inadequacy to
maintain a proper degree of warmth is very quickly
experienced.   There is,  besides, the smoke diffi-
culty—a problem for large  towns becoming year
by year one of greater  magnitude and less capable
of solution.
  Bituminous coal—the kind used for the  manu-
facture of illuminating gas, and everywhere em-
ployed for  consumption on the  domestic hearth—
when burnt in an open  fireplace gives off three
times  its weight  of   carbonic  acid gas, small
quantities  of carbonic  oxide,  sulphurous acid,
bisulphide of  carbon, and sulphuretted hydrogen—
all these being  poisonous and injurious gases—
and, in addition, steam (water vapour).   No less 
WARMING
123
than one per cent, of the coal is given off as fine
solid particles of unconsumed carbon and  tarry
matters, commonly called soot.
  The example of London will show how vast  are
the polluting effects of smoke upon the atmo-
sphere.  In this great city it is computed that on
a cold winter's day as  much as 40,000 tons of coal
may be consumed in the twenty-four hours.   The
smoke  given  off from the 800,000  houses con-
stituting modern London will carry into the air in
this one day some 400 tons of  soot, and  probably
a,n  equal amount of sulphur as sulphurous  acid;
also 120,000 tons of  C02 gas will be added to
London's atmosphere.  It  is true that these pol-
luting ingredients are  spread more or less over a
large area (seventy to eighty  square  miles);  but
in  stagnant  conditions of the atmosphere  (anti-
cyclones) there is also the cumulative effect—the
pollution of one day not being carried off before
the fresh accession of smoke on the following day
or  days.   These figures,  at  any rate,  help  the
ordinary observer to realise the origin  and con-
tinuance of  yellow fogs, and the factors  upon
which they depend.
  The common  form of  open  fireplace is a good
deal more wasteful of fuel  and heat than there is
any necessity for.   The open space under  the
lower bars admits cold air to the burning fuel and 
124         THE ELEMENTS OF HEALTH

chills it, causing at  the sa\ne time imperfect com-
bustion and waste of fuel.   The sloping back to
the grate throws a vast  quantity of heat up  the
chimney, which might, under better  management,
be radiated into the room; and this  result is con-
tributed  to  by the  too great depth of the  grate
and the too large opening into the chimney flue.
  Certain improvements  have been carried out in
the construction of open fireplaces,  many  of  the
suggestions here detailed originally emanating from
Mr. Pridgin Teale, of Leeds (Fig. 23).
  (1) The width of the grate  facing the  room
should be considerable, whilst the depth is curtailed.
In this way  the radiating surface is increased, and
more heat is utilised.   (2) The back and sides of
the grate should be made of fire-clay, which, being
a very bad conductor, does not permit the escape
of heat  in undue quantities into the  wall of the
room.   (3) The back of the grate should be curved
forward, " rifle-backed " as it is called, to permit of
the flames playing upon the  curvature, which in
turn radiates its heat towards  the room.  (4)  The
floor of  the grate  should either be formed of a
solid slab of  fire-clay, or,  preferably, the  lower
fire-bars may be retained, and a hot-air chamber
contrived under them by fixing an iron shield on
the hearth  to  cut off  all access of  air to the fire
from beneath the fire-bars.  The grate is thus  ren- 
                   WARMING                125

dered " slow combustion," whilst the space beneath
the] fire-bars is useful in forming an ashpit, into
which  the  consumed  ashes fall, and from which
they can be removed by pulling forward the shield.
                     Fig. 23.
       Slow-combustion  Open  Fire-place
  It is wonderful how completely in these slow
combustion  grates the coals are consumed.  A
little reddish-grey ash results, but no large cinders 
126         THE ELEMENTS OF HEALTH
are seen.  Cinders mean incomplete and wasteful
combustion.  The  grate  with  the  solid fire-clay
bottom gives equally good results as regards com-
bustion, but the fire is apt at the end of the day to
become  clogged from the accummulation of ash,
which in  the  other arrangement  falls  into  the
ashpit.
  To economise heat, the fireplace should stand as
far forward in the room as possible.   The chimney
throat should  be limited in area to  prevent  the
undue  escape   of heated air;  and the fireplace
should, wherever possible, be fixed  in an inner—
not an outer—wall of the house.
  So much for economy  of fuel and utilisation of
heat; and it may here  be stated that  a modern
open firegrate  on improved principles very quickly
pays for its cost in a diminished coal bill, not to
mention the increased comfort.
  As regards the avoidance of smoke or its limita-
tion, this  is a  matter which greatly concerns  the
urban householder, but which, of course, individual
effort is unable to cope with.  The use of hot-water
pipes, steam pipes, and stoves on the Continental
system for the heating  of houses is repugnant to
the tastes and feelings of most of the inhabitants
of these islands, and neither  have  such methods
any hygienic  advantages.  By some the use of
anthracite,  or  smokeless coal, is  recommended, 
WARMING
127
to be  burnt in specially designed grates, as the
common form of fireplace is not very suitable for
this form of coal.   It is doubtful, however, whether
the anthracite collieries now working have sufficient
of this coal for the supply of domestic fireplaces
on a large scale.
  Others recommend so-called smokeless or smoke-
preventing grates.  In  one form  of  these grates
the fire is " underfed," that is to say, the supply of
fresh fuel is  introduced beneath the incandescent
coal, which forms the top of the fire,  and through
which the gases arising from the fresh coal must
pass, thus securing a more complete combustion
than is possible where the  fresh fuel  is placed on
the top of the fire.  These grates are  undoubtedly
economical, and continuously expose  a clear fire
free  from  smoke, but they  require more care and
attention  and greater trouble in stoking than the
ordinary  firegrate, and for this reason are never
likely to become  very popular; or, if  used, to be
properly attended to.
  The  third remedy,  and the one in  which there
is most promise,  if only coal  gas were half its
present price, is the replacement of the open coal
fire by an open gas fire.   In the usual  form of  this
appliance the flames from  a row  of  atmospheric
burners, i. e. burners  in which air is allowed to
enter and mix with the gas before it  is burnt, so 
128
THE ELEMENTS OF HEALTH
as to produce a  non-luminous blue flame—play
upon  asbestos in  lumps or fibre, which  becomes
highly heated, but  is otherwise unaffected, being
indestructible by heat. With coal gas at 3s. per 1000
cubic feet, gas fires are certainly more costly than
coal fires; but they  possess the great advantage of
being smokeless, causing no accumulation of soot
in the chimney, and  no dust and ashes in the dust
pan.  No fire has to be made with paper and sticks;
they are immediately lighted when wanted, and at
once extinguished when their use  is  no longer
required.
  Although they  give out no coloured smoke, it
must always be remembered that there are products
of combustion which, although invisible, are highly
injurious;  and a flue to carry off these products to
the open air must invariably be provided.
  The coke and gas  fire is a cheaper substitute for
the continually burning gas fire.   A row of gas
burners need only be fixed under the lower fire-bars
of an ordinary coal grate, in which is placed coke as
obtained from gas-works.  The coke  is lighted by
the heat of the gas flames playing on it from below ;
as soon as it begins to be red-hot the gas can be
extinguished, and the coke continues to burn until
it is consumed.  Fresh coke can  be placed on the
red-hot coke in the  grate without any further use
of the gas.  In fact, the  gas  is  only required to 
WARMING
129
set the coke,  at first starting, thoroughly alight.
As already said, the products of  combustion of
coke contain carbonic  oxide  gas—a  most deadly
gaseous poison—and for  this reason coke fires
should be recommended with  caution.
   In G-alton's  (Fig. 24) and the Manchester School
Fire Grate an open coal fireplace is made the means
of introducing fresh warmed air into the room.
A chamber lined with fire-clay is constructed in
the brickwork at the back and sides of the grate,
which  becomes warmed by the  heat  of the  fire.
An opening  is made  from  the  bottom of the
chamber to communicate with the outer air, and
introduce the  latter into the chamber;  whilst
another opening is made  from the chamber into
the room above the level  of the chimney-piece,
to allow the warmed air  to escape into the room,
and thus  effect the  ventilation of the apartment
with warmed fresh air.
   Other means of  heating houses are stoves in
which  coke, coal,  oil, or gas is  burnt, hot-water
pipes  in  connection with a boiler,  and  steam
pipes.
   Heat is  radiated from these  appliances just
as from open  fireplaces,  but this source of heat
is of but little account compared with the warming
of the  room by means  of  convection.  The  stvoe
or hot-water pipe coils stand out bodily in the
                                      9 
130
THE ELEMENTS  OF  HEALTH
room, and are not placed in the face of one wall

with an open tube to the outer air  above them

                    Fig. 24.
Warmet Air
 Colo
f-AiR
Ventilating  Open Fire-place 
WARMING
131
as open fireplaces are.   The rx»m is warmed by
currents  of warm air.  The an  • Mssing over the
stove or  coils of hot pipes beco.ues  heated, rises
towards the ceiling, imparts its heat to surround-
ing cooler objects, becomes cooled in consequence,
and  sinking towards the floor, again flows towards
the  source of heat, to  undergo  the  same round
of movement.   The  room is  therefore warmed
by circulating  currents of heated air, that is, by
convection.
  The warmth is very  much more evenly distri
buted throughout all parts of the apartment than
is the case with radiant heat,  the   intensity  of
which is inversely as the square of  the distance
from the source of heat; by which is meant that
an  object 6  feet from   an  open fire,  or  other
source of radiant heat,  receives only one-fourth
the  amount  of  heat that an object  only  3 feet
distant from the source of heat receives—namely
as 9, or the square of  3, is  to  36, or the  square
of 6.
  With  stoves there  is always great economy of
fuel, for the  heat is utilised in the room, and only
sufficient air is supplied to  the  burning fuel  to
support combustion, there being no open  chimney,
with its continually  changing column  of  heated
air to be maintained at  a  high temperature,  in
order that the latter may escape. 
132
THE ELEMENTS OF HEALTH
   Notwithstanding these  advantages there  is the
 great  sanitary  drawback that  stove-  or  pipe-
 heated dwelling-rooms  are generally close, stuffy,
 charged with  overdry air, and  occasionally evil-
 smelling.   The  closeness and stuffiness are  due
 to want of ventilation;  the  overdrying of  the
 air is  due to its high  temperature, the moisture
 present being insufficient to  produce the proper
 amount of relative  humidity; and the smell is
 commonly  caused by  charring  of  the  organic
 matter in  the air, as it  passes  over the highly
 heated surface of the stove.
   Stoves and  hot-water pipes are not, therefore,
 to be recommended for use  in ordinary dwelling-
 houses.  They are, however,  useful for warming
 the halls and staircases of  large mansions; and
 in churches, chapels, concert rooms, public  halls,
 and assembly rooms, the maintenance of a proper
 standard of  temperature without  their employ-
 ment is hardly possible.
   There are several  desiderata  with  regard  to
 stoves which maybe mentioned. (1)  "Ventilating"
 stoves (Fig. 25), which introduce a supply of warmed
fresh air into the room in which they are  fixed,
are preferable to " close " stoves.  A pipe from
the outer atmosphere conducts air into a compart-
ment in the stove, separate from the combustion
chamber, in which it is warmed, and then escapes 
WARMING
133
into the air of the room.   (2) A vessel of water
should be placed on the stove, to  supply moisture
to the air by evaporation.   (3)  Stoves of china
                     Fig. 25.
Ventilating  Close. Stove:
orkfire-clay should be preferred to cast-iron stoves,
unless the combustion chamber of the latter sort
is  lined with  fire-clay.   The metal of the  cast-
iron stoves  becomes  too  highly heated as a ru1 
134         THE ELEMENTS OF HEALTH
with the result of the  charring  of the  organic
matter  in  the  air, and the  production  of  a
" burnt" smell.
  There is no objection to heating large buildings
with hot-water pipes on  the low pressure  system,
in which the water  does not rise  above 200° F.,
but means should always  be adopted for the intro-
duction of  fresh air over  the  coils,  and  its
continuous  supply to  the room ;  and the  pipes
should never be placed in chased depressions  in
the walls, or in channels in the floor, but should
be so fixed that the duster and broom have access
to the spaces beneath and behind them. 
LIGHTING
135
                 CHAPTER V

                    LIGHTING
 Daylight illumination of rooms—Artificial lighting: Electric light,
                 Gas, Lamps, Candles.
   Abundance of light and air  are essential for a
 healthy  dwelling.  Houses in which the dwelling-
 rooms are dark and sunless, are not only cheerless
 and dismal, but are also undesirable on the score of
 health.  The dark places of a house  are those
 where dirt is most likely  to  accumulate, and least
 likely to be removed.
   Modern research shows that there  is no greater
 sweetener of foul matters in  the  atmosphere than
 sunlight and fresh air.  Direct sunlight is capable
 of destroying microbes of the most pestilent species,
 and of the most  persistent  forms.   It  follows,
 therefore, that the rooms of a  house which  are
 most freely exposed  to the  sun are  likely to be
 not only more cheerful, but also more healthy than
 those which the sun's rays rarely visit.
  A south aspect  is to be recommended  for the
living-rooms of a house,  as  the sun's rays must
penetrate at some time or other of the day.  In 
136
THE ELEMENTS OF
HEALTH
summer, a room with an unobstructed south aspect
is likely to be too highly illuminated, and at this
season,  of  course, sun-blinds  or Venetian  blinds
must be used to darken the room when necessary.
For certain classes of work, a  room with a north
aspect is to be preferred, as the light proceeds from
the sky, and not directly from  the sun, and is  con-
sequently more subdued and steady.
  The area of the windows of a room  should  bear
some proportion to the size of  the room, that  is to
say, to the  floor area.  The window  area  should
not be  greater than one-fourth  the  floor area,
and not less than one-tenth  that area.   If   the
windows are too large, the  room is difficult to
warm in winter, as the great expanse of thin glass
allows of an undue escape  of heat.  If the windows
are insufficient in size, the room is badly lighted,
dark, and  cheerless.   The window should reach
nearly to the ceiling of the room, so as to allow of
the light playing upon  the  ceiling, from which it
will be reflected to all parts of the room ; and also
to permit of the ventilation of the higher parts of
the apartment,  where foul  and heated  air is
especially likely to accumulate.
  Window-glass in the smoky atmosphere  of our
large towns speedily becomes coated with soot and
dirt, and much of the light may thus be  cut off.
The thorough cleaning of the outside of the window 
LIGHTING
137
is not always possible, unless the person engaged
in the  work  is willing to assume a  position of
some danger by  sitting  or  standing upon  the
window-sill.  It would be  well if all windows of
rooms at a height  above the  ground  were fitted
with reversible window-frames, which  can  be re-
volved upon an axis, so as to present the outer
surface  to the interior of the room.  All cleaning
can then be done from the  inside of the house.   In
Millar's  patent the  sashes can be taken  off the
stiles altogether, and replaced without taking  off
any of the beads, or  disturbing any of the wood-
work about the frame.
  The best position for  writing is to sit with the
window on the left-hand side, so that the light may
fall on the paper, and no shadow be cast  by the
hand or pen, if the writer  is right-handed.  It is
better not to face the light directly, and thus the
dazzling effect of strong light  in the  eyes may  be
avoided.
  The artificial lighting of a room is a matter of
considerable  importance, as the  eyesight is likely
to be damaged by bad arrangement, or insufficient
quantity, or quality of the light.   What is required
is  that  the  object  we are regarding  should  be
steadily  and  sufficiently illuminated,  whilst  the
eyes themselves are protected  from strong rays of
light. 
138
THE ELEMENTS OF  HEALTH
  On the whole, perhaps the incandescent electric
light  answers these requirements  best; but oil
lamps, gas, and  candles  may  be made  to  give
satisfactory illumination.   One great advantage of
the electric light is that there are no products of
combustion to pollute  the air  of  the room, the
incandescent  filament of carbon being enclosed in
a glass globe containing nitrogen gas, which does
not support combustion.
  If gas jets are used, care  should be taken that
the supply of gas  is regulated, so that  flickering
or jumping of the flame may be avoided.   A flame
of this character is very trying to the sight.   This
result may be attained  by the use of the  so-called
" regulating burners," or by having a gas governor
attached to the gas main close to the meter.   It is
also not advisable  to have the gas jet  or burner
too near a wall, ceiling, or  other cold surface, as
the unconsumed carbon particles  from  the  flame
will be deposited on  such  cold  bodies,  causing
them to become coated with a layer of soot.
   The Welsbach  incandescent  gas  burner is  a
very suitable one   for dwelling-rooms, as  it  gives
out a very steady white  light.   The light  from
the incandescent  asbestos  gauze mantle is not
nearly so yellow as the light from an  ordinary gas
jet.   The Regenerative gas burner of Siemens is
more suited for large halls, and gives out a strong 
LIGHTING
139
 and brilliant light for the gas consumed.   In this
 appliance the air and gas, previous to their union,
 are  heated  in  chambers surrounding the  flue by
 the waste heat  of the combustion.
   Lamps are more dangerous than gas jets, as the
 latter as a  rule are  fixtures,  and not liable to
 overturn; whilst the lamp, being a movable object,
 is liable to this form of  accident.   A danger also
 arises in lamps from the  fact that it is very often
 the custom with careless people to blow the flame
 out, and subsequently to depress the  smouldering
 wick into the reservoir  holding the oil;  the
 vapour  of the  oil becomes ignited, and  an ex-
 plosion  ensues.   The best duplex lamps are now
 provided with extinguishers, to obviate the blow-
 ing out of the flame; and in all safety lamps there
 is a mechanical arrangement by which, if the  lamp
 is upset,  the flame  is immediately extinguished.
 The  sale of highly inflammable and dangerous oils
 is now prohibited by Act of Parliament, and there
 is practical safety if only care and reasonably good
 lamps are used.
   Candles are dangerous, if only for the fact that
there is a naked flame; but it is often the  custom
to provide the candle flame with an ornamental
shade, which is apt  to catch fire if not attended
to, or if the candle is exposed to a draught.  The
risk is thereby very greatly increased. 
140
THE ELEMENTS OF HEALTH
                 CHAPTER VI

  HOUSE CONSTRUCTION IN ITS SANITARY ASPECT
Damp houses and disease—Subsoil air and subsoil water—Pollution
   of the subsoil—Prevention of dampness in houses—Ventilation
   under floors—Bad design in the planning of houses—House-
   hold dust—Floors, walls, and ceilings.
  Warmth and dryness in a house are as essential
to health  as good drainage and  adequate ventila-
tion.  If the house walls are damp or  the site is
water-logged, the dwelling  cannot be otherwise
than unwholesome.
  The atmosphere of a damp house is not only
moist, but cold also, the warmth of the  interior
being utilised, not to warm  the  air of the  house
and objects  in it, but to evaporate the  water con-
tained in damp walls  and floors.   A large amount
of heat is absorbed in  the process of evaporation
of water  by reason  of the  change of condition
from fluid water into  vaporous steam, and this
heat, thus rendered latent, is in consequence lost
to the  house.  It is  the universal experience of
medical men  that many diseases  of  the  lungs
(bronchitis,  pneumonia, pleurisy, and  phthisis or 
  HOUSE CONSTRUCTION IN ITS SANITARY ASPECT 141

consumption),  rheumatism, and  ague  are very
often associated with residence in damp houses on
moisture-laden sites, and excessive mortality from
diphtheria, measles, and whooping-cough is very
commonly observed under similar conditions.
  In  certain low-lying situations, such  as river
valleys, the subsoil water—that is to say, the rain
which has percolated from the surface through
porous soil—is  found at a depth of only a few feet
from  the surface of  the  ground.   This subsoil
water fills all the interstices of the porous earth,
and the vapour which arises from it by evapora-
tion  is found in  the  air occupying the layers  of
soil above the underground water-line.
  Various natural causes such as winds, changes in
the pressure and  temperature  of  the atmosphere,
and a rise  in the level of the subsoil water, cause
the displacement of this ground or subsoil air, and
its escape  at the surface  of the  earth.  It is, of
course, in freely porous soils such as loose sands
and gravels that the ground air is largest in amount
relatively to the soil, and most  easily set in motion.
In the  dense  and less permeable soils, such  as
clay and  heavy  marls, the ground air  is  of less
consequence.
  Owing  to  the  above-mentioned natural causes,
aided very often by the in-suction caused by fires
within the house, the  ground air  finds its way 
142
THE ELEMENTS OF HEALTH
 through the surface of the earth into the interiors
 of houses; and holding, as it  may, watery vapour
 to saturation, it  introduces  into the  house much
 undesirable moisture.
   Ground or subsoil air is not only unduly moist,
 it is also charged with impurities of an unwholesome
 character.  In the surface layers of the  soil are
 found the various microbes that  cause the  fer-
 mentation and putrefaction of  organic matters.
 These matters are changed in the surface layers of
 the subsoil, as if it were a laboratory, into simpler
 inorganic constituents that  become the  food of
 plants.  The importance of this natural function of
 the surface soil is  at once apparent, as without its
 beneficent action  waste and useless organic sub-
 stances would litter up the surface of the  earth,
 and plant life would  languish for want  of the
 mineral salts necessary  for its maintenance.
   All the same, however, the processes of disinte-
 gration carried on in the soil are productive of
 gases and vapours  which pollute the air, and are of a
 character prejudicial to health.  This being so, even
 in virgin soil,—that is to say, soil which has not been
disturbed for building, drainage, or other purposes,—
it  follows that the  precautions necessary to prevent
soil emanations finding their way into houses from
ground which has  been long built upon, or which 
  HOUSE CONSTRUCTION IN ITS  SANITARY ASPECT  143

has become contaminated with filth and rubbish,
must be even more necessary.
  In towns where  the streets  and the  general
surface of the ground  are largely covered  with
impermeable paving, which prevents the escape of
air from  the soil, there is a  very great tendency
for  the displaced ground air to find its way into
buildings.  The contamination of the ground air in
inhabited places is most  commonly due  to  the
filth which escapes  from leaky cess-pools,  drains,
and sewers, but this  air may also become mixed
with coal  gas from  defective underground gas-
pipes.   Serious and even fatal  coal-gas poisoning
has been known to afflict the occupants of houses
into which such polluted air has found an entrance.
  Another serious cause of pollution of the subsoil
is the presence of crowded  graveyards and ceme-
teries  in  the  midst  of inhabited districts.  The
enormous amount of decomposing material  con-
tained  in the soil of many of our urban cemeteries
can be realised when it is understood that it used,
years  ago, to  be the custom to bury numerous
bodies  in one grave—one above  another, until but
a foot or so  of earth  rested upon the last-placed
coffin.  Overcrowding of burial  places still con-
tinues, but not to the same extent as prior to the
Burials Act of 1855.
  In some outlying districts  around towns much 
144
THE ELEMENTS  OF HEALTH
of the virgin gravel is removed by builders, and
the excavations so made are filled  in with house
refuse collected from  domestic  dustbins.   These
plots of so-called "made ground" are subsequently
built  upon, and the  dwelling-houses  so erected
rapidly become notorious  as being "never  free
from fever and illness."
  It is, then, a very important sanitary desidera-
tum, when houses are being erected, to prevent the
possibility of the entrance of  ground air by cover-
ing the entire  site  under the building with a bed
of good, thick  cement concrete, at least 6 inches
thick, rammed  solid.   Especially necessary is this
when houses are erected on impure or moist ground.
Although so important a measure from the  health
point of view, the concreting  of the site is  seldom
effectually carried  out, even in the case of houses
which will command a large rental.
  Houses are  rendered damp  not only by the
evaporation of moisture from  the subsoil  water,
but also by the property that water has  of ascend-
ing in  porous substances by  what is  known as
"capillary attraction."  If the  end of  a  porous
substance, such as a brick, is just dipped in water,
the water soaks into the pores  of  the  brick, and
rises  vertically until the whole  of the brick  is
moistened.  This is the result of capillary attrac-
tion.  Consequently, if the footings of a brick wall 
HOUSE CONSTRUCTION IN  ITS SANITARY ASPECT 145
are resting upon  or  surrounded  by damp earth
(Fig. 26), the moisture in the earth will invade the

                    Fig. 26.
              Damp  Wall
                   FROM
        Defective Foundations

porous bricks,  and will gradually rise in the walls,
                                    10 
146
THE ELEMENTS  OF HEALTH
 rendering them cold and  clammy.   The  large
 amount of water that may be  contained in a damp
 wall will be realised  when it  is understood that a
 brick of ordinary size—measuring 9 inches by 4^
 inches, and  3  inches deep—will hold some 16
 ounces of water.
   Dampness is usually visible in  brick walls, the
 moist bricks being darker in  colour  than the dry
 ones.  The surface, too, will often feel wet to the
 hand.   Should the bricks be covered by  plaster
 and wall paper,the paper will discolour and eventu-
 ally peel off the  wall.  In time various growths  of
 fungus are visible on the damp surfaces—usually
 seen as  white, black, or reddish-coloured spots or
 masses, consisting of very  fine gossamer-like fila-
 ments.   The timber  and  woodwork of  a  damp
 house are very liable  to decay owing to the attacks
 of similar fungoid organisms.
   To prevent dampness in a house owing to exces-
 sive moisture in the subsoil, several precautions
 must be observed in its original construction, and
 in the preparation of its site.  As regards the site,
 subsoil drains  should  be laid at a depth  which will
be below the level of  the foundations, in order to
carry off subsoil water and to  prevent its rising to
the footings of the walls.  These drains  should be
formed of unglazed, porous earthenware pipes laid
end to end, without  sockets  or joints, so as to 
  HOUSE CONSTRUCTION IN ITS SANITARY  ASPECT  147

 permit the water in the soil to percolate readily
 into them.  The drains should be  carried through
 the  ground to discharge, at a lower level, into a
 ditch or  stream.  They must  not, of course, be
 directly  connected with any sewer, cesspool, or
 drain used for the reception of house sewage.
  In some places a naturally damp subsoil may be
 effectively rendered dryer by  this  system of
 drainage, and the level of the subsoil water be
 permanently lowered.
  To prevent the house walls becoming damp from
 contact with  moist  earth,  the footings  of  every
 wall should rest upon a bed of concrete; and above
 the footings a damp-proof course should be inserted
 in the brickwork, which will effectually prevent
 moisture ascending from below upwards (Fig. 27).
 The  damp-proof  course  must  consist  of  some
 material which is impervious to moisture, such as
 slates laid horizontally and embedded in cement,
 a horizontal layer of asphalte from  half to  one
 inch thick, or  a course of glazed stoneware slabs.
  To prevent  dampness in the cellars or basement
 of a  house, in addition to  the damp-proof course
 which is  usually laid above the ground level, the
 external walls should be separated from the ground
by  an open area, extending upwards from  the
house foundation to the ground level (Fig.  27);
or in cases where there is no space available for an 
148
THE ELEMENTS OF HEALTH
open area, the walls of the house below the ground
should be double, so  as to enclose  a vertical air
                    Fig. 27.
Wall with  Dry Area  &  Damp-proof  Course
 space, which prevents the transmission of moisture 
  HOUSE CONSTRUCTION IN ITS SANITARY ASPECT 149

from the outer to the inner wall.   The two  walls
are bonded together by iron  ties, to  secure the
proper stability.
  It is very important in ground floor rooms that
the joists supporting the  floor boards should not
be laid on  the earth. There should always be a
space of about 2 feet left between the ground and
the joists, and this space  must be well ventilated
by  openings through the  external  walls, which
may be covered outside by iron gratings to prevent
the entrance of vermin.   If the space under the
floors is not well ventilated, dry rot is pretty sure
to attack the woodwork  and  cause its destruc-
tion.
  The space  between the floors in the basement
storey and the earth is very apt to harbour cock-
roaches,  ants, mice,  and  other   objectionable
vermin.  The basements of some houses  in towns
are  rendered  almost  uninhabitable  from  this
cause.  The  only  effectual remedy is to remove
the flooring, and  the top layers of  earth, and  to
lay a bed of concrete over the entire surface.  The
top of the concrete can be floated  with  cement,
and finished  to form the flooring, thus getting rid
of all woodwork,  and depriving vermin of  every
possible place in which they can shelter.
  The  ground  around  and  in   the immediate
vicinity of  dwelling-houses should be paved with 
150        THE  ELEMENTS OF HEALTH
impermeable  material,  so  as  to  prevent  the
formation in wet weather of stagnant liquid pools,
the water of which soaks into the ground around
the house  foundations.   Areas and yards may
be  paved with cement concrete, asphalte, blue
glazed  bricks,  or  York  flagstones;  and  the
surface  should be sloped  to carry away storm
waters  to gully traps and  the  drains.   Cement
concrete and asphalte  are preferable to bricks and
flagstones,  as in the latter  there are the joints
between the bricks and flags, which are apt to
become in course of time open or unsound.
  Dampness may  arise from other  causes than
from the ground.  It will  be sufficient merely to
indicate them.   (1)  Driving  rain  in  exposed
situations,  especially  where  the  mortar  joints
between the bricks are laid bare from defective or
worn-out pointing.    (2)  A water-pipe which is
embedded  in  a wall  may be  leaking.   (3) A
cistern may be overflowing, and the water soaking
into adjacent brickwork.   (4) A  rain-water gutter
or  a  rain-water pipe may be choked or defective,
and in  consequence  the rain-water drips down
the walls, instead of  running away  at once  to a
drain.
  The dampness due  to leaky soil-drains under a
house has  been  already  mentioned.   In  some
instances the dampness has been traced to an old 
  HOUSE CONSTRUCTION  IN ITS SANITARY ASPECT 151
cesspool in the ground under a house, the contents
of which soak away into the soil.
  Not only must the walls of a house be dry, but
they should also be of proper thickness, to  protect
the inmates from those seasonal changes of tem-
perature  incidental  to  our  climate.  A  wall
of proper  thickness  will  protect  from cold  in
winter, and  from  heat in  summer.   When the
house  is warm, a thick wall minimises the escape
of heat by radiation from inside to outside; and
in hot weather the interior of the  house is main-
tained at a cool temperature, the rays of the sun
being unable to  raise the interior of the wall to a
high  temperature  owing to its  thickness.  The
material of the  wall—brick, stone, or concrete—
is of  less importance in this respect  than  its
thickness.
  A  good deal  more  might  be  done than  is
generally attempted at present to  make the roof
of the house abetter non-conductor of heat.  The
attics of most houses  are unbearably hot in warm
weather, and  the reverse in cold.  If the inside
of the  roof under the slates  were  lined  with
matchboarding and  a thick layer of  felt,  the
attic  storey would  be a more comfortable abode
than is generally  the case now.
  Bad design in the original planning of a house
may render it an undesirable residence  from the 
152         THE ELEMENTS OF HEALTH
health point of view.  Architects and  builders of
the present day are very much more  conversant
with the sanitary principles of  house  design and
construction than were their predecessors of thirty
years ago.  It will be sufficient to enumerate some
of the  more important  desiderata, hygienically
speaking, of house design and planning.
  (1) The floors of the ground floor rooms should
always be raised well above the level  of the out-
side  adjoining  ground.   In former days cottages
and small country houses very commonly  had the
ground-floors  depressed  below  the level of the
adjourning ground, with the result that the walls
were  often damp, and there  was  no  ventilation
under the floors.
  (2) The staircases, passages, and landings should
be well  lighted  and ventilated.   A  central stair-
case  lighted by a skylight in the roof  is very
commonly seen in large mansions, but  its ventila-
tion  cannot  be  so  satisfactory  as  where  the
staircase is lighted and ventilated by external side
windows.  In many houses  now occupied  by the
poorer classes, the staircase is in the centre of the
house, and is absolutely dark and unventilated.
Many of these are tenement houses, i.e. occupied by
several  families; and not only does the staircase
form  a shaft for the conduct of foul air from one
tenement to  another, but  the  risk  of  infection 
  HOUSE CONSTRUCTION IN ITS SANITARY  ASPECT  153

spreading in houses of this class is very greatly
enhanced, should one of the occupants be attacked
by a communicable  disease.
  (3) The rooms intended for  occupancy by  day
or night should have windows  opening into wide
open  spaces,  not  overshadowed by surrounding
buildings.   The non-observance of  this  rule is
most markedly developed  in the construction of
mansions let in flats and artizans' dwellings in  our
large towns.  In very many cases inhabited rooms
will  be discovered which  are  exclusively lighted
and ventilated from narrow enclosed courtyards or
shafts hemmed in by buildings  of colossal height,
which render impossible the access of the neces-
sary light and air.
  (4) The height of the rooms  should  not be  less
than eight  feet.  In many of  the  older class of
cottage buildings,  rooms  of seven feet or even
six feet six inches  are to be found.   In  this class
of two-roomed cottage property it is not unusual
to enter the ground floor room directly from the
street, and to  find an  open  stairway or ladder
running directly from the lower room to  the upper
room,  the latter receiving as  a consequence the
used and vitiated air of the former.
  (5) The sanitary  conveniences of a house—the
water-closet,  bath-room,   lavatories, &c.—should
not  be situated in the centre  of  a  house,  but 
154
THE ELEMENTS  OF  HEALTH
should be placed against an outer wall, in order to
secure light and ventilation direct from the outer
atmosphere.  This is a matter which  has already
been discussed.
  (6)  Every living room of a dwelling-house should
have through light and ventilation ;  that is to say,
there  should be windows  on opposite sides of the
room, or window  and door on opposite sides, in
order that the air of the room  may be thoroughly
renewed by  allowing air currents to  pass right
through.  Houses built back-to-back,  or so con-
structed that the rooms are lighted and ventilated
from one side only, are less  healthy  than those in
which the design  secures through ventilation.
  A dwelling-house should not only be sound in
design  and strong and dry in structure, but the
internal fixtures  and furniture  should  be such as
to permit  of  the interior being kept clean and
wholesome with the least  expenditure of time and
energy.
  Household  dust  is  the debris  resulting  from
household life and activity.  If  some of this dust,
which  has  been  deposited from the air  in an
inhabited room,  is examined microscopically,  it
will be seen to consist of soot particles in abun-
dance, sand particles, cotton and wool fibres, starch
grains, pulverised straw or vegetable matter, epi-
thelium from the epidermis of  men and  animals, 
  HOUSE CONSTRUCTION IN ITS SANITARY ASPECT 155

spores  of fungi  and bacteria,  &c.  Much of it
is  evidently  organic  refuse,  and  therefore  a
waste  product to be removed from our habita-
tions with  the greatest  possible  frequency and
regularity.
  Whilst the  production of  this dust  may be
regarded as inevitable  in all  inhabited houses,
still the internal  fittings may be so arranged as to
render its collection as easy as possible.  It is well,
first of  all, to remember that the dust  represents
the  suspended matters that  settle out  of the air,
when at rest, upon all  objects  in a room; there-
fore every part of the  walls and floor  of a room,
and every surface of  objects  in the room,  should
be   accessible  to the  housemaid's broom  and
duster.
  Any  surface  which is  inaccessible,  but  yet
affords  a resting-place on which dust is deposited,
is to be deprecated.  As such  may be  mentioned
cornices and  headings or other projections upon
ceilings and above doors and windows;  cumber-
some articles of  furniture, as sideboards, book-
cases, and wardrobes, which collect dust  on their
upper surfaces, and are too heavy to be moved to
allow dust to be swept out below.  Besides these,
dust collects to a considerable extent in  rough or
flock wall  papers, in carpets, curtains,  canopies,
and draperies; and in consequence all  such dust- 
156
THE ELEMENTS  OF  HEALTH
holders should be frequently removed to the open
air  to have the accumulated  dust  beaten out of
them.
  Rough  or  flock wall-papers are decidedly ob-
jectionable,  and  should be  replaced by  papers
having a  smooth non-absorbent surface.   Whilst
the room is being re-papered, particular care should
be given to ascertain  that the old paper, and any
papers of still more  ancient date, are peeled off
until  the  plaster is exposed, before the  new paper
is applied.
  Floors  with crevices between the shrunk and
warped floor-boards are an especially bad form of
dust-trap, as  dust and dirt fall through the crevices
into the space between the floor and the ceiling of
the room below, from which position no measure
short of taking up the floor can remove them. Defec-
tive floors of this kind can be entirely covered over
with linoleum or oil-cloth, or, preferably, with thin
oak parquetry, kept  well  polished with oil and
beeswax,  as the use of oil-cloth tends to produce
rotting of the woodwork below.  Solid wood-block
flooring, in which the blocks are dovetailed, without
chinks or crevices, are now much used.  With such
flooring, or with parquetried floors, carpets to cover
the whole area of the room are not  required, and
the use of squares of  carpet, rugs, and mats is en-
couraged—that is  to say, of articles of small size 
 HOUSE  CONSTRUCTION IN ITS SANITARY ASPECT  157

which can  without inconvenience be frequently
shaken and cleared of dust.
  Bedroom walls should be planned with recesses,
to be utilised as cupboards, drawers, and shelves,
and  thus render unnecessary cumbersome ward-
robes and chests  of  drawers.   The actual bed-
room furniture  can  then  be  reduced   to  the
necessary  bed,  washstand,  dressing-table,  and
chairs, and no surface  is presented for the depo-
sition of dust  which  is not  readily accessible.
Distemper colouring is better  for bedroom wall
surfaces  than wall-papers;   and especial  care
should be given  that the floor surface is in sound
condition,  without  chinks and  crevices  for the
lodgment of dust;  and that its surface  is not
covered with  carpet.  A few mats are permissible
in a  bedroom ; but a carpet, which merely receives
an  annual  shaking or beating, should  not  be
tolerated.
  In choosing wall-papers for a house alwaj^s insist
on being supplied with papers which are guaranteed
free  from arsenical or other poisonous pigments, as
the use of arsenical papers has been credited rightly
with the production of severe illness amongst the
occupants of rooms so papered.
  Parian  cement coated with paint laid  on to a
fine,  smooth  surface,   forms  an  excellent wall;
but the room so painted should  not be inhabited 
158
THE ELEMENTS OF HEALTH
until the paint is thoroughly dry, and all " smell
of paint" has departed.  Nearly all paints contain
lead salts as a  basis, and in drying some of  the
lead salt is evaporated, or as a powder mixes with
the air of  the  room, and may be productive of
symptoms of lead-poisoning.
  Where expense is not a consideration, the walls
and floors of water-closets, bath-rooms, and lava-
tories should be either lined or covered with glazed
tiles set in cement;  or the floor may be formed of
tesselated pavement, consisting of small chips of
marble  set in cement, whilst  the walls may be
cemented and subsequently painted. 
SITE  AND SITUATION OF HOUSE       159
                CHAPTER  VII

         SITE  AND  SITUATION OF  HOUSE
 Varieties of  soil — Exposure of site — Elevation — Bracing and
     relaxing localities—Influence of vegetation and water.
   To most people it is  not  given to be able  to
 choose  the exact locality where they shall live.
 Their choice is limited at any rate to the district in
 which they find employment;  and such questions
 as are involved in  considerations  of  climate, site,
 and situation are necessarily subordinated to those
 of convenience and proximity to  employment.
   It may  be generally stated that there are  but
 few  localities  in this country which are centres
 of any  industry which cannot be rendered whole-
 some and  healthy by efficient drainage, sewerage,
 and water-supply, and by insistence on the  obser-
 vance of sanitary principles in the construction  of
 the houses.  To those who have  a wider range  of
 choice in the selection of where they shall live, the
following observations may be of service.
  The warmest and driest soils to live upon are the
gravels  and sands,  because they  are the most 
 160        THE  ELEMENTS OF HEALTH

 absorbent of heat, and the most porous  to water.
 In this moist and fickle climate of ours it is certainly
 healthful to reside on a warm and dry soil.
  The porous soil must, however, be of considerable
 depth, and not underlaid at a short distance  from
 the surface by a bed of  clay, which prevents the
 passage of water.  Porous soils which are water-
logged in this way are often extremely damp and
 unhealthy;  and  it would appear that when the
 underground conformation is such  as  to pond, or
 enclose the subsoil water, as it were, in a dish, so
 that it is rendered stagnant, the unhealthiness  is
 very  considerably  accentuated.   In  many  river
 valleys there is a good bed  of gravel on the sur-
 face,  and although the underground water is not
 far from the surface, yet with proper  precautions
 the site is healthy, because the underground water
is not stagnant, but is continuously though slowly
 moving with a defined current in  the direction of
its natural outlet.
  Marshy and alluvial soils (the latter to be found
near the estuaries of rivers) should be  avoided  on
account of their dampness and the impurity of
their  ground air.  Containing as they  do  much
vegetable organic matter, which is in  a continual
state of change and fermentation, they are credited
with the production of malarious diseases and rheu-
matism, and are not fit sites for human habitations. 
SITE AND SITUATION OF HOUSE       161
   It is needless to observe that houses should never
 be chosen to live  in  which are believed to have
 been erected upon excavations filled in with refuse
 and rubbish, or upon the sites of  disused burial
 grounds.
   Clayey soils  are colder and damper than gravel
 and sand of considerable depth.   They  are  cold
 because  less absorbent of heat, and damp because
 they are impervious to a considerable  extent, and
 yet retentive of moisture.
   Chalk, when of considerable thickness, is usually
 very dry, but being little absorbent of heat is cold.
   Mixtures of these soils, and other varieties  of
 soil, are  cold or warm, dry or damp, more or  less,
 according to their absorptive powers for both  heat
 and water;  but rocks which, like granite and slate,
 are quite impermeable to water, are of course only
 affected by heat and  the rays of the sun, and are
 uninfluenced by moisture.
   Those  who suffer from catarrhs, bronchitis, rheu-
 matism, or other diseases attributed to cold  and
 damp, should choose dry, warm soils to  live upon.
 To many people, however, soils which  are warm
 and dry prove too relaxing, especially in  summer,
 and better health is  enjoyed  on  a  more bracing
 soil.
   It is difficult  to say why some localities are brac-
ing and others relaxing, these qualities no doubt
                                      11 
162
THE ELEMENTS OF HEALTH
depending very  largely  upon  different circum-
stances in different places and at  different seasons
of the year.  As  a general  rule  it may be  stated
that places which are considerably elevated, which
are exposed  to winds from  the  north and east,
and of which the soil is cold, are bracing;  whilst
those which are sheltered from the north and east,
which are low-lying, and stand upon thick beds of
gravel or sand, are relaxing.
  It is, then, to a  considerable extent a question
of cold and heat.   Cold is bracing and invigorating
all over the world; heat is relaxing and enervating.
In summer  the bracing places  on the east  and
north-east coast are most sought;  and such places
as possess  a dry  and sandy soil, which becomes
much heated  by the sun, rendering the air over-
hot, too dry, and enervating, are avoided.   In the
winter the warm  dry soils of the south coast, with
their shelter  from cold winds  and their exposure
to the south and the sun, are the  resorts of those
in search of health and pleasure.
  What is healthful and desirable in the hot season
is not equally so in the  cold  months  of the year.
High elevations, bleakness of site, and exposure to
cold and wet winds are often trying in winter, even
to the robust; whilst in hot weather  such  places
are healthful  and restorative  for  the  weak  and
debilitated. 
SITE  AND SITUATION OF  HOUSE       163
  For a  house which is intended to be used as
a residence all  the  year round, it  is  generally
advisable to choose such a situation as will afford
the happy medium between the  extremes.   If a
south aspect sheltered from the north by rising
ground, cliffs, or trees is chosen, and  the  soil  is
sandy or gravelly, it is usually advisable to culti-
vate trees and vegetation to temper the summer
heat.  Vegetation and  herbage protect the  soil
from the sun's rays,  and  cool  the air by  the
evaporation of moisture from green leaves.
  On cold and damp soils trees and vegetation are
less necessary, except as a protection from  cold
winds.   It is certainly not advisable in  any  case to
have trees so close to the house as to interfere with
the free circulation of air around it.   Where there
is excessive moisture in the soil, vegetation is of
use in evaporating large quantities of water and so
drying it; but where the ground is cold and not
damp, absence of  vegetation and exposure to the
sun  is most effective in warming the surface, and
so avoiding extremes of temperature.
  The immediate proximity of  ponds and lakes
should be avoided, as such collections of stagnant
water are apt  to render the air in the  neighbour-
hood of a house unduly cold and moist at certain
seasons of the year.
  A situation on  a  slope is generally  considered 
164
THE ELEMENTS OF HEALTH
advantageous, favouring as it does natural drainage
both on the surface and in the subsoil.   Elevation
above the surrounding country is  also  considered
an attractive quality, as it gives an extended view,
and ensures as a rule purity of air. 
FOOD
165
                 CHAPTER  VIII


                        FOOD

Classification of foods—Composition of foods—Animal and vege-
    table diets—Digestibility of various foods—Cooking—Variety
    and admixture—Meal-times—Appetite: mastication of food—
    Excessive meals—The digestive process—Soups, broths, and
    jellies — Meat,  fish, tinned  foods — Oysters, eggs — Milk:
    Mother's  milk and cow's  milk,  Suckling  and hand-feeding,
    Infants'  foods, Sterilisation  of  milk, Storage  of milk—
    Butter and cheese—Bread—Farinaceous foods—Fresh vege-
    tables and  fruits—Condiments—Alcoholic beverages : Malt
    liquors,  Wines,  Spirits—Tea, coffee, and  cocoa—Mineral
    waters.

   Food is  necessary  to repair the  wasted tissues
of the body, and to enable growth to go on during
the period  of immaturity and development.
   There are six  chief classes  of  food, namely,
Proteids, Fats,  Starches   and  Sugars,   Vegetable
Acids, Mineral Salts, and  Water.
   All these six different food substances should be
adequately  represented in the diet  of  man, and
inasmuch  as no  one food  contains  all  the sub-
stances  in  the  proper  proportions,  a variety  of
different kinds of food is for this reason alone a 
166
THE ELEMENTS OF HEALTH
necessity.   Hence the  proper diet  of  man  is
essentially a " mixed diet."
  The proteids are the only food substances con-
taining nitrogen, and as  this element enters into
the constitution of every tissue of the  body, and
some of it is excreted daily as a waste product of the
wear and tear of the tissues, it follows  that a cer-
tain proportion of nitrogen-containing food must
be given in the  diet,  to  repair the  bodily  waste.
Until  growth is completed,  nitrogenous  foods
have another  function   besides that  of  repair,
namely, the formation of new or additional  tissue,
and  the  gradual  evolution  of the mature and
perfected structure from its immature and  imper-
fect  condition.
  The proteids are contained in both  animal and
vegetable foods. The flesh or muscles and the blood
of  animals  contain  albumen,  fibrin,  syntonin,
myosin, and globulin; whilst milk contains casein,
and the white of an egg is nearly pure albumen :
all  these substances belonging  to the  class of
proteids.   Vegetable foods also contain proteids :
thus gluten exists in wheat, barley, maize, oats,
and  rye flour; and legumin is found in peas  and
beans—both gluten and legumin being nitrogenous
substances.
  It is a remarkable  fact that all these different
members of the  proteid class are of nearly equal 
FOOD
167
 nutritive value, and therefore mutually replaceable
 in the diet of man.
   The fats of a diet are derived almost entirely from
 animal sources—from the fat of meat (dripping)
 and from  the  fat  of  milk  (butter).   Fats  are
 necessary to repair and build up the  fatty tissues
 of the body, to yield energy for mechanical labour,
 and to keep  up the bodily temperature. The yield-
 ing  of energy and the maintenance of the bodily
 temperature are brought about by the oxidation of
 the  fatty food, and its conversion into  carbonic
 acid and water.
   The  sugars and starches, which  are  derived
 chiefly from the vegetable kingdom, have similar
 functions in the body to the fats.   They therefore
 serve, like the fats, as fuel for the body, in much
 the  same way as coal  does for the steam-engine.
 Although their functions are more or less identical,
 fats are not replaceable in the diet  by starches
 or sugars, nor starches and sugars by fats.
  The vegetable acids  exist in fresh vegetables,
 fruit, meat, and milk—chiefly in the two former,—
 but not in these articles when dried or preserved
in tins.   They are important constituents in a diet,
as in their absence the  health suffers and scurvy
eventually results.
  The mineral  salts are contained in nearly all
animal and  vegetable foods in a  greater or less 
 168        THE  ELEMENTS OF HEALTH

 degree.  They are essential for the repair, growth,
 and maintenance of all the various  tissues of the
 body.
  Water enters into the constitution of all the so-
 called solid foods,  but  must  be taken  as well
 separately as a drink,  as the amount contained, in
 the solid foods is insufficient for the  needs of the
 body. The body is constantly losing water, exhaled
 in the breath  and excreted in  the  sweat, urine,
 and faeces,  and these  daily losses must be made
 good.   Water  is  the vehicle  for  the  dilution
 and solution of the solid  foods  in the alimentary
 canal, and is  necessary for the  elimination from
 the body of most of its waste products.
  The following table  shows the  percentage com-
 position of  some of  the chief articles of  food in
ordinary use.
In, 100 parts.
				Starches	
	Water.	Proteids.	Fats.	and	Salts.
				Sugars.	
Cooked Meat	54	27 5	155		3
White Fish	78	18	3		1
Bread (fine, white, wheaten)	36	7 1	05	55-2	1
Oatmeal ....	15	126 ,	56	63	3
Peas (dry)	15	22	2	53	2-4
Potatoes ....	74	2	0*16	21	1
Butter ....	6	33 l	88	_	2-7
Cheese ....	368	335 |	243	_	5-4
Milk (cow's)	87-5	34 i	36	4-8	07
Egg (without shell) .	74-5	125	12	— '	1
 
FOOD
169
   For a man engaged in ordinary work the daily
 diet should contain—
      Proteids     .    .    .     4*5 oz.  av.
      Fat    ...    .     3-5   „
      Starches and sugars   .    14'0   „
      Salts   ....     1-0   „

                               23-0
   That is to say, 23 ounces of  dry,  solid (water-
 free) food must be taken every  day to enable the
 work of the body to be properly performed.
   Inasmuch as  ordinary food contains from 50 to
 60 per cent, of water, the  23 ounces must be
 multiplied at least by 2, if the diet is to be stated
 as ordinary  food (not water-free).  And from 50
 to 70 fluid ounces (2£ to 3£ pints) of water must
 in  addition  be  drunk  to  supply the  needed
 quantity.  This quantity will of course vary with
 the amount and nature of the exertion, and the
 temperature and moisture  of  the  atmosphere.
 During arduous exertion in  a  hot climate  very
 large quantities of water may be needed.
  As before  stated, all the  different classes  of
 food substance  should be  adequately represented
in a diet; and it is certainly a  matter for congratu-
lation that the  costliness of the various kinds of
food  bears no  very  great  proportion to  their
nutritive  values,  otherwise  the  poorer  wage- 
170
THE
ELEMENTS OF HEALTH
earning classes  would be unable to  supply their
wants, and would be in a continual state of semi-
starvation. The vegetable foods, bulk for bulk, are
far cheaper than the animal  foods, but the proteid
substances they contain, although smaller relatively
in amount,  are just as  capable of  maintaining
life as the proteids of  the higher-priced butcher's
meat,  fish, game,  and eggs.   The diet  of  the
lower  wage-earning classes is largely composed of
wheaten  bread, potatoes, dripping,  cheese,  and
occasionally  bacon  or  the  cheaper   kinds  of
butcher's  meat.   Taking bread, potatoes, drip-
ping or margarine, and cheese alone,  we see that
a daily consumption of bread 2 pounds, potatoes
£ pound,  dripping or margarine  2  ounces,  and
cheese 8 ounces, would provide  the labourer with
nearly 5  ounces of proteids, 3f ounces of  fat,
nearly 20  ounces of starches, and nearly 1  ounce
of mineral salts.  The cost of this daily food with
bread at 5d. the 4-pound  loaf, potatoes at Id. per
pound, margarine or dripping  at 8d. per pound,
and cheese at  6d. per pound, would amount  to 7d.
  A  diet  of this character  might  be suitable for
an agricultural labourer,  whose entire day is spent
in laborious work  in  the  open air,  and   whose
digestive  powers  are  of the  keenest, but  would
prove  very distasteful to the  town mechanic, the
factory hand,  or  the person  engaged  in  any 
FOOD
171
sedentary indoor occupation.  Not less important
than  the theoretical  nutritive value of the food
is its capacity for easy digestion and assimilation
in the  alimentary canal; and there can  be no
doubt that the diet above given would be of little
real   value  to the  class of  town  mechanics and
factory   operatives  on  account of  its  want  of
variety, its sameness, and monotony.
  Putting  aside the  state of health of the indi-
vidual in its bearing upon the processes of diges-
tion, the digestibility of food depends partly upon
the nature of the food in its raw state, partly upon
the effect produced upon the food by the operation
of cooking, and to some extent upon its admixture
with other foods and accessories.
  In  the first place the proteids derived from the
animal kingdom are more completely digested than
those obtained from the vegetable,  although  it
does not follow that  the vegetable proteids—such
as may be capable of digestion—give more work
to the digestive  organs than the animal proteids
do.  It is no doubt, however, the fact that animal
fats are more easily digested than vegetable fats.
The fat of cocoa, for  instance, is much less easily
digested than the fat of butter.
  The flesh of  different kinds of animals varies  in
the rapidity  with which it  is digested, and pro-
bably  also  in its  capacity  for  easy  digestion. 
172
THE ELEMENTS  OF  HEALTH
Figures are sometimes given of the  number of
hours various kinds of food remain in the stomach
before passing into the small intestine.  No great
reliance can be placed upon these figures as being
capable of general application, inasmuch  as the
experiments have been  limited  in number, the
observations being necessarily only possible in the
case of gastric fistulas in  man—a gastric  fistula
being  an  artificial   opening  into  the  stomach
through the abdominal walls, by which its interior
can  be examined.  These experiments show that
veal and pork remain longer in the stomach (over
4 hours) than mutton or beef (3 to 4 hours) ; and
this  coincides  with  the everyday  experience  of
the comparative indigestibility of pork.
  Cooking is necessary to increase the digestibility,
palatibility, and appetising qualities of the food,
and to destroy parasites  or noxious microbes that
may be present.  The various kinds of  starchy
foods such as potatoes, wheat flour, rice, peas, &c,
are extremely indigestible in an uncooked condition.
These starchy foods consist of minute grains, each
grain having  an  outside coating of cellulose pro-
tecting the starch within.  The  cellulose  coat is
comparatively unaffected by the digestive  juices,
but when heated to a sufficient degree in the process
of cooking the cellulose envelope bursts open and
the digestible  starch within is  set free.   Most 
FOOD
173
vegetable  foods  gain weight  in  the process of
cooking by absorbing water.
  Animal foods taken raw are little less digestible
than when well cooked, and are more digestible
than when badly cooked.   But cooking renders
meat more savoury, various aromatic vapours being
generated which are distinctly appetising, and the
warmth of recently cooked  food is  also an  advan-
tage and an aid to digestion, not  to  mention the
destruction of  possibly existing  parasites  and
noxious germs. Animal foods lose weight in cook-
ing owing to the loss of moisture they sustain.
  If meat is cooked too long or at too high a tem-
perature it becomes hard, tough, and  indigestible.
Most  of  the proteids  in  meat—fluid  or semi-fluid
in raw meat—coagulate or solidify between the
temperature of 155° F. to 165° F. and in  so doing
they render the meat  fibres hard and solid, whilst
the juices escape, with the result that the food be-
comes dried up, tough, and indigestible. In cooking
joints of meat, whether by roasting, baking, or boil-
ing, the primary object is to rapidly coagulate the
outside of the  joint by submitting it to a high tem-
perature for a few minutes, and so by forming an
externalprotective coating prevent the undue escape
of the internal juices and thus leave the interior
of the joint in  a semi-coagulated state, the remain-
der of the cooking being conducted at a  tempera- 
174
THE ELEMENTS  OF HEALTH
 ture insufficient to cause the interior of the joint
 to rise above 155° F.—the coagulation point of the
 proteids.   During the process of cooking, the con-
 nectivetissue between thebundles of muscular fibres
 is broken down and converted into gelatine, which
 escapes in a liquid condition with  melted fat, and
 some of the salts of the meat, to form the  gravy.
 This destruction of the connective tissue loosens the
 fibres of the meat from each other, and renders it
 more easy to chew and masticate in the mouth.
  The admixture of different classes of foods greatly
 aids their digestibility.  The common custom of
 eating meat with vegetables and bread is a sound
 one.  If meat was eaten at one meal and vegetables
 alone at another,  the digestive  powers would be
 much more severely taxed.  The various  food ac-
 cessories  and condiments also  have an important
 effect upon digestion, chiefly by stimulating  the
 flow of saliva and  gastric juice.
  We have seen that man should live upon a mixed
 diet,  consisting of  proteids, fats,  starches  and
 sugars, vegetable acids, salts, and water in certain
 definite amounts and  proportions.   The weighing
 of definite quantities of foods, and the apportion-
 ment of definite  weights of the chief foods daily to
 each individual,  is not usually undertaken outside
barracks,  prisons, and public institutions, nor  is it
necessary in ordinary households.   Amongst the 
FOOD
175
poor the question of meals is chiefly one of expense,
whilst with  the  better-to-do  classes  it  must be
chiefly one of convenience and appetite.
  In  order that  the full benefit of food may be
obtained, it is important that judicious selection of
the articles of diet should be made, that they should
be carefully cooked or otherwise  prepared for the
table, that the admixture of different kinds of food
should be judicious,  and that the meals be taken
regularly, at intervals not  too far  apart  for the
proper recuperation  of  the frame  and  the main-
tenance  of the highest degree of energy, but not
so short  as to involve too great a strain upon the
digestive organs, by reason  of these organs being
kept in a continual state of activity.  The individual
can exert great influence upon his digestion of the
food by the  cultivation of appetite, by the proper
mastication and trituration of the food in the mouth,
by avoidance of excess in quantity, and by abstain-
ing from food which  is too rich, highly spiced,  or
otherwise  undesirable   in  quality,  and  by the
avoidance of very active exertion, bodily or mental,
immediately  after meal-times.
  At every  meal there  should  be  a proper ad-
mixture  of  proteids, fats,  starches, aud  sugars.
The customs of civilised society ensure this prin-
ciple  being put into  practice;  mixed food,  such
as bread, butter, eggs, milk, meat, vegetables, &c, 
176         THE ELEMENTS  OF HEALTH

being almost invariably  associated, to  a greater
or less extent, at every meal.  In addition to this,
there should also  be a certain  amount of  daily
change and variety  to obviate the distaste that
is likely to arise  when there is too  much  same-
ness and monotony in the  articles of food offered
to the palate.  Bread, butter, and milk  are daily
indispensables, but it is not  difficult to secure the
desired variety by changes  of  meat, vegetables,
and  fish, the  different  kinds  offering  a  large
variety of choice.
  Most important  of  all  is the proper cooking
and  preparation of food.   It is undoubtedly true
that a good cook with limited resources and cheap
articles of  food can prepare a  more  appetising
and  digestible meal than a bad cook  can with the
best appliances and the most costly fare.   The
teaching  of cookery on  sound principles is now
very rightly engaging a good deal of  public atten-
tion, and forms a part  of most technical education
courses.
  The number of  meals  each day,  and the times
at which  they should be  taken, must next engage
our  attention.   As  an average, it may be said
that three meals a day  is the right number for
adults.    Allowing eight  hours for  sleep,  there
will  be sixteen waking hours in the  day.  If the
first meal, or breakfast, is  taken  at the end of 
FOOD
177
the  first waking hour, the  next meal, dinner  or
lunch, need not  be taken until five  hours after
breakfast,  and the final meal, supper  or dinner,
as the  case  may be,  not for five  or six hours
later.
  This allows a period for digestion of five hours
between every meal; and inasmuch  as there is no
certainty that the food of one meal has evacuated
the stomach until four  or four and a half hours has
elapsed after  its ingestion,  it is  evident that five
hours is by no means  too long a time to allow to
intervene between  consecutive  meals.  For it is
certainly not desirable to introduce fresh food into
the stomach until the  stomachic digestion of the
preceding  meal is  completed, and  the stomach is
left in a condition favorable for the reception of
fresh food.
  For the  man who gains his living by the work
of his muscles, the  midday  meal should  be  the
principal one.   For the brain-worker, however, the
evening meal is generally chosen  as the chief
meal, or dinner; and  there is much to be said in
favour of  an arrangement which allows of diges-
tion  being carried on during  hours of   relaxa-
tion.  If the evening meal is deferred to  too late
an hour,  the  result  is  not so  satisfactory, for
during sleep  the digestive processes are more  or
less in abeyance, and the  retention  of   incom-
                                      12 
178
THE ELEMENTS  OF HEALTH
pletely  digested food in the stomach gives rise to
dyspepsia and troubled sleep.
  For children, growing youths and girls,  and
delicate persons, four  meals a day are often to be
preferred  to the three meals, a lesser quantity
being taken at each  meal to counterbalance the
greater frequency.
  The cultivation of appetite is more or less within
the power of  the individual.   Want of appetite
may be due to bodily illness requiring medical
treatment, with which we are not here concerned.
But in otherwise  healthy  people,   a deficient
appetite may be due to want of proper exercise in
the  open air.   Where  there  is little  muscular
energy there is but little waste of tissue, and  the
call of the tissues for repairing food is  but little
felt.  Again, the blood may be deficiently aerated
from want of fresh air and  exercise; and when in
this condition its function of removing waste  pro-
ducts from the tissues, and supplying them with
nutriment for their repair, is but inefficiently  per-
formed, and the failure of the appetite is but the
index  of  the unhealthy condition of  the system.
Loss  of  appetite  may also be consequent  upon
over-fatigue, mental or bodily, and too long or too
short  intervals between  meals.   All these  are
matters usually capable of adjustment,  if  their
importance is only understood; and that they  are 
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179
important is readily comprehended when we know
that loss of appetite means impaired  digestion
and defective nutrition of all parts of the body.
  The proper chewing of the food is also an im-
portant  element in  digestion.   The  object  of
mastication is to break up  the  food into small
fragments, of  which the component  parts  are
easily separated, and to allow of these becoming
thoroughly incorporated with saliva.  The small,
loosely  adhering fragments are readily attacked
by  the gastric juice when  passed into the stomach,
whilst the  alkaline  saliva induces the flow of the
acid gastric juice.   To swallow  or " bolt" large
fragments of food which have not been masticated,
is to introduce that which cannot be acted upon
by  the gastric  juice, and which  becomes  instead
the prey of putrefactive microbes, undergoing in
time  fermentative  changes, with the production
of  foul gases—setting up in fact acidity, flatu-
ence, gastric pain, and other symptoms of  diges-
tive disturbance.
  A  meal  excessive  in  quantity may  produce
similar  results.  If  more food is  taken than the
stomach can conveniently  digest, the  excess  is
unacted upon by the digestive juices, and is liable to
undergo fermentation, and cause  irritation to the
stomach and intestines.   An  excess  of any  one
constituent of the meal may lead to similar  results, 
180
THE ELEMENTS  OF  HEALTH
e. g. an excess of starches or sugars, which are very
readily  acted upon by  bacterial ferments,  or an
excess of fat, which rapidly decomposes into  fatty
acids.   A  diet  which  is habitually  too  rich in
proteids, as in the  case  of excessive meat eaters,
tends to produce troubles of its own.   The kidneys
become overtaxed in getting rid of the excess of
nitrogenous waste, the blood is imperfectly purified,
containing  waste substances  which the excretory
organs are  incapable of  sufficiently removing  from
it, and liver  disease, gout,  and  other troubles
follow.
  The question of the number of times a day meat
should  be  eaten  does  not  admit of  a dogmatic
answer.  As  a rule the  wealthier classes eat too
much meat at a  time, and eat it too often. There are
many who, after reaching middle age, would be
better in health for limiting themselves to a  meat
meal twice a  day.   But no rule for universal  guid-
ance can be laid down.  The tendency towards over-
indulgence in eating is  directly fostered amongst
the  wealthier classes by the  large  use made in
cooking the food of spices, sauces, and condiments.
Dishes  so  prepared create  an artificial appetite,
which is not sated  when enough food has been
eaten to satisfy the wants of the body—as  would
be the case with a natural, healthy  appetite.   The
diversity of food also, and  the excellence of the 
FOOD
181
 cooking which prevails in wealthy households, lead
 similarly in the direction of excess.  It cannot be
 too strongly stated that food of a simple character,
 well cooked, and cleanly served, is more produc-
 tive of healthy  living than  abundance of dishes,
 and piquant  sauces which create a craving for
 food in excess of the bodily needs.
   During the process of digestion in  its earlier
 stages, the blood-supply to the digestive organs is
 largely increased.   Any special activity of a bodily
 organ leads to an increased demand for blood, and
 its consequent supply.   Hence the importance of
 rest, or at least of the avoidance of very active bodily
 or mental exertion  subsequent to a good meal.  If
 the muscles or the nervous system are very actively
 employed during  the digestive process, blood is
 withdrawn  from the  digestive  organs, in con-
 sequence of the increased demand for  blood  for
 the muscles and brain.   The digestive  process in
 consequence is  hindered,  delayed,  or  actually
 arrested, with the result that fermentative changes
 take  place  in  the food instead  of the normal
 digestive changes.
  It cannot be too  clearly comprehended that  all
food which is introduced into the stomach must be
properly digested,  otherwise  dyspeptic  troubles
arise.  Food which from any of the various reasons
we  have  been considering  does  not  undergo 
182         THE ELEMENTS OF HEALTH
normal  digestion, becomes subjected to the action
of  the  putrefactive  and  fermentative  microbes
present in all parts of the alimentary tract.  The
fermentation  of  the  food  in  the stomach  and
intestines is incompatible with  a normal state of
health; and  if such fermentative action is con-
tinually supervening, changes of structure are at
length  induced in  the secreting glands and the
mucous  menbrane  lining  the   alimentary  canal,
which constitute actual organic  disease.
  Large quantities of water or other fluids should
not be  consumed during the progress of a meal.
It is not desirable to dilute the gastric juice in the
stomach to too great an extent, or to  chill that
organ with a large volume of cold  liquid.  Thirst
should  be  relieved half an hour before the com-
mencement of a meal; the water so introduced will
have been absorbed into the blood before the food
reaches the stomach.
  There is no objection, but generally some advan-
tage, in the taking of a small quantity of hot soup
or broth before the  heavier viands are  attacked.
Soups and broths contain gelatine, salts, and ex-
tractives from meat and bones, and certain aromatic
products.  They are,  therefore, food-accessories,
the extractives and aromatic products also tending
to stimulate the appetite, and promote the flow of
gastric juice. 
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183
  Bones are rich in gelatine, fat, and salts, and are
far too valuable, as producers of broth and soup, to
be thrown away.  Gelatine is a proteid, but is not
the nutritive equal of the other members of the
proteid class, as it cannot form nitrogenous tissues.
It may, however, prevent excessive tissue  waste,
and is useful on this account in the  dietetic treat-
ment of fevers, where excessive tissue waste is in
progress.  Jellies largely  consist of gelatine. It
must be clearly understood, however, that jellies,
beef tea, broths, and soups  are  not foods of any
considerable value.   They cannot  build up  new
tissues  or repair wasted  tissues.  They are chiefly
valuable in the dietary of sickness as stimulants of
digestion, enabling other foods of more constructive
quality to be assimilated.
   In making beef tea,  broth, or soup, the meat
used must  be  chopped into  small  pieces,  and
covered with cold water, with the addition of some
salt.   The heat should  be applied very gradually
and  steadily, and the water never allowed to  boil,
in order to avoid the coagulation of the proteids,
which would  prevent the passage  of extractives,
salts, gelatine, and fat into the liquid,  which is the
object aimed at.
   Meat.—Immediately after the death of an animal,
the  proteid body known as  myosin, of which the
muscles are  chiefly  composed,  coagulates, this 
184
THE ELEMENTS OF HEALTH
coagulation being known  as rigor mortis.   After
a time, the length of which depends somewhat on
the weather, the  myosin again becomes  soft and
semi-fluid, and the meat is more fit for  cooking.
Meat as obtained at the butcher's has often been
derived from an animal only recently killed, hence
the necessity for " hanging," which should be done
in a dry, clean, and airy larder.   The hanging must
of course be terminated before the development of
any putrefactive  taint.  A joint of butcher's meat
(beef or mutton)  should be firm, elastic,  and of a
deep red colour on section—not too pale, and yet
not purple or livid.  Veal  and  pork are much paler
than beef and mutton.  The odour should be fresh,
and not unpleasant, and there should be no taint of
putrefaction.  The joint  should be free from excess
of moisture, but  in certain states of  the weather
even  good  meat  is apt to drip with a reddish-
coloured fluid.
  Frozen meat should be thoroughly thawed for a
day or longer before it is cooked.  It takes a con-
siderable time for the interior of a large frozen j oint to
thaw. If the meat is cooked before it is thoroughly
thawed, the result is never satisfactory.
  Meat should be cooked as thoroughly as possible
in order  to destroy any noxious  organisms  or
poisonous substances it may contain, but,  as before
said,  the  cooking  should  not be  carried  to  the 
FOOD
185
point of rendering the meat tough and indigestible.
Pork especially should be thoroughly well cooked.
" Measles" is not an uncommon  disorder in pigs,
and  unless the cysticerci (the little  cystic bodies
found  in measly pork)  are destroyed  by heat,
they may cause tapeworm in anyone who consumes
them.   It is a usual rule to allow at least a quarter
of an hour in cooking  for  every pound that the
joint weighs.
  An important essential in all cooking operations
where an oven is used, is the proper ventilation of
the oven.  If the oven is not ventilated, the meat
becomes sodden  in  its own vapours,  and is  dis-
agreeable to the taste.   Gas  cooking ovens are
very cleanly and convenient, and their temperature
can  be  regulated with great nicety by adjusting
the consumption  of gas;  but it  is most essential
that the oven should be ventilated, otherwise the
meat becomes impregnated with the products of
the  gas  consumption, and decidedly injurious.
There should be a  flue attached to the  oven to
carry off these products to  the outer  air.  With
these precautions there is no perceptible difference
between a joint baked in a gas oven, and one
roasted before an open fire.
  Tinned meats are useful supplements  to butcher's
meat.   Great  care  should  always be  taken to
reject  any kind of  canned or  tinned  provision 
186
THE ELEMENTS OF HEALTH
which, on opening the tin,  evolves a disagreeable
or suspicious odour.  Very serious poisoning effects
have followed the  consumption of tainted food of
this character.  It must also be remembered that
these preserved foods do not contain any of those
antiscorbutic principles which  afford protection
from scurvy, and which are present more  or less
in all classes of fresh meat, fish, and vegetables.
  Fish, unlike meat, unless cured or dried, should
always be eaten as fresh as possible.  Tainted fish
often produces severe poisonous effects.  The oily
fishes like herring, mackerel, salmon, and eel, are
less digestible than  the non-fatty fish, e.g. soles,
plaice, cod, turbot, and brill, which  are  highly
digestible forms of food.
  Most kinds of game may be eaten with impunity
when they have become " high," or, in other words,
passed into an incipient state of putrefaction.
  It must not be too confidently assumed that
cooking will make tainted  butcher's meat  or fish
harmless.  It would appear that often the processes
of cooking are unable to render such food  edible,
the poisonous  bodies which have been formed in
the flesh not being destroyed by the heat of cook-
ing.  Poisonous alkaloidal substances may be pre-
sent in the flesh  of diseased animals, and may not
be rendered innocuous when such flesh is  cooked.
It is also believed that the unwholesomeness  of 
FOOD
187
certain  kinds of meat and fish, which are out of
season, may be due to alkaloidal poisons.
   It is not always just to lay the blame for illness
attributed to food upon the tradesman who supplies
it.  Uncleanliness in the kitchen may be productive
of  un wholesomely prepared food.   Especial  care
should be bestowed on the cleanliness of cooking
utensils made of copper.  Verdigris—an oxide of
copper—is very apt to form unless brightly polished
surfaces are  constantly maintained.   The  same
remarks may be held to apply to  tinned cooking
utensils.
   Oysters and some  other varieties  of shell-fish
are usually eaten raw.  Oysters, having  relatively
to their size very large  livers, are  largely com-
posed of glycogen or liver starch, which is highly
digestible.  They form, therefore, a valuable food
for invalids and people of feeble digestive powers.
   There is some risk, however, in the consumption
of raw  oysters, as these  shell-fish  are frequently
cultivated in water which receives  sewage  and
human  excrement.  It  is  asserted that oysters
fatten best  in sewage-polluted waters, so that it
may be much to the interest of the oyster-farmer,
who wants to send his produce to the market in
the primest condition, to fatten his  fish on what
probably, being a waste product, costs him nothing.
  Reliable evidence has  of late accumulated as to 
188         THE ELEMENTS  OF  HEALTH

the infection of typhoid fever having been commu-
nicated by oysters, or at any rate by consumption
of the polluted water contained within the oyster's
shell.
  With such considerations in view it would appear
to be  a wise precaution to  cook oysters before
sending them to table.   Oyster epicures, who may
consider their  favourite dish  spoilt by cooking,
should  at  any rate submit to  the  oyster  being
taken  out of its  shell and well washed in clean
water before consumption.
  Eggs are highly nutritious.   Hens' eggs contain
about 12 per cent, of proteids, and the same quan-
tity of fat.  This  fat is  contained in the yolk of
the egg, whilst the white of the egg is nearly pure
albumen (proteid).  Eggs are most digestible when
perfectly fresh and lightly boiled.  In  a  hard-
boiled  egg the albumen  of the white is strongly
coagulated,  and less easily attacked by  the  diges-
tive juices than is the partially coagulated albumen
of a lightly boiled egg.
  Milk is  the  natural food of  infants and  young
children.  For the first six or  nine months of life
the infant thrives best on its mother's milk;  subse-
quent  to  this  period cow's milk answers  every
purpose.
  The compositions of  human and cow's milk are
as follows: 
FOOD
189
Average Percentage Composition by weight.
	Human milk.	Cow's milk.
Fat	. 2-9 .	. 3-5
Proteids .	. 3-0 .	. 4-9
Milk sugar	. 5-9 .	. 4-0
Salts	. 0-2 .	. 0-7
Total solids	. 12-0 .	. 13-1
Water	. 88-0 .	. 86-9
   In all the milks secreted by different mammalian
 animals, the proteids, fats, salts, and water exist
 proportionally  in  much larger  amount,  as com-
 pared  with the starches and sugars,  than is the
 case in the ordinary food of the adult animal.  The
 reason is that the  proteids, fats, and  salts are
 required in large amounts for the rapid growth of
 the body, whilst the water is necessary in equally
 large  amount  for the  quick formation of tissue,
 and for the rapid removal from the body of waste
 products.
   It will  be seen from the above table  that the
 composition of cow's milk is different from that of
 human milk.   There is an excess of proteids, fat,
and  salts, and a deficiency  of milk sugar in the
former as compared with the latter.  This is one
reason why cow's milk is  unsuitable for infants.
There are, however,  two other weighty reasons.
  Firstly, the curd which is formed in the infant's 
190
THE ELEMENTS OF HEALTH
 stomach by admixture of the milk  with the acid
 gastric juice, is quite different in the case of cow's
 milk from that characteristic of human milk.  The
 curd of human milk forms a flocculent mass, the
 particles of which being loosely held together are
 readily attacked  by the digestive  juices; whilst
 cow's milk clots in dense putty-like  masses, which
 are with difficulty digested.  The  curd consists of
 the  proteid  and  fat of the milk,  and therefore
 contains its most nutritive properties.   The un-
 digested curd  of cow's  milk gives rise to fer-
 mentative  changes, flatulence,  and gastric pain,
 and much of it may be  passed  unchanged in the
 motions.  The child vomits curdled milk, and has
 constant diarrhoea, and although taking plenty of
 nourishment fails to thrive.
  Secondly, human milk drawn from the mother's
 breast by the sucking child is sterile and free from
 any form  of   microbe  life;  whilst the hand-fed
 child usually draws its milk  from  a  dirty feeding-
 bottle, the milk containing microbes and ferments,
 which hinder  proper digestion, and are all too
 liable  to set up  mischief in  the  infant's delicate
organs.
  Ass's and  mare's milk are much more  nearly
 identical in composition with human milk than is
the cow's secretion.  Goat's milk is rather too rich
 in fats, but ass's, mare's, and goat's milk are all 
FOOD
191
superior to cow's milk  for the human infant, inas-
much as they form a loose, flocculent, and digestible
curd in the infant's stomach.
  Suckling for the first six months is not only best
for the infant, but as a general rule for the mother
as  well.  Suckling beyond the ninth  month  is
usually disadvantageous  to  both—the  mother's
health becomes weakened by the prolonged drain
upon her strength,  and the  child  requires after
this period somewhat stronger sustenance.
  If an infant must be hand-fed, the cow's milk
should be  boiled, to  destroy noxious  microbes;
it should be diluted with water, and should receive
an addition of milk sugar to make its composition
approximate more  closely to mother's milk.   It
should  be given in a cleansed and scalded  bottle
without internal tubes or other parts difficult to
clean.  The old-fashioned boot-shaped bottle is
far preferable to the more modern one with a tube.
To obviate,  as  far as may be,  the formation of
putty-like  curds in the infant's stomach, some
pearl  barley water,  well boiled  and  strained,
should  be  added to the milk in the  bottle.  The
gum-like substance  in the barley water  has  the
mechanical  effect  of preventing the  particles of
curd  coming into too  close  apposition, and  the
curd thus formed is looser and more easily broken
up  than  when the  cow's milk is given  alone. 
192
THE ELEMENTS  OF  HEALTH
The mother or nurse should never forget to warm
the contents of the feeding bottle to the tempera-
ture of the child's body—98° F.
  Some of the larger dairy companies now retail
a  so-called "humanised" milk, artificially pre-
pared to resemble  human milk  in its composition.
This  is  sterilised by  heat, and  sold in sealed
bottles.
  Infants and  children should never be fed ex-
clusively upon condensed milk, infant's foods, or
other preserved articles.  Infantile scurvy—a very
dangerous disease—is likely to  follow the use of a
diet in which fresh food has no part.  These pre-
served foods are deficient in the vegetable acids
which are  contained in new milk, and which are
as essential for  the maintenance of  health in the
young as  in the adult. Many of the  condensed
milks, besides, are very deficient in fat, being made
from  "separated,"  that  is,  "skimmed" milk.
They contain, too, as a  rule,  far too muchsugar.
"Separated,"   "skimmed,"   or  "butter-milk/'
means in  its application to milk, the withdrawal
of the whole or the greater part of the fat.  Such
milk, deprived of its cream or fat, cannot supply
to a child the nourishment it needs.
  Sterilised milk is now being supplied for nursery
use.   The process of heat  sterilisation tendw to
cause the milk  to separate into curds and whey; 
FOOD
193
and besides, such milk may have been prepared at a
date long anterior to its use, and is in consequence
no longer " fresh."  It would appear to be better
that  milk  should be boiled in  the  house imme-
diately after its delivery, and then be  consumed
without delay.  The importance of giving children
fresh food cannot be over-estimated.
  Milk is still far too largely consumed in an un-
boiled condition.  Most people have heard of milk
epidemics of diphtheria, scarlet fever, and typhoid
fever, and yet the simple precaution of boiling the
milk, and so destroying  any possible germs of
disease it may contain, is very generally neglected.
There is not only the occasional  risk of epidemic
disease,  but the  ever-present possibility  of the
mixed milk  of numerous  cows  containing the
bacillus of tubercle.
  Tubercular disease is comparatively a  common
illness of  dairy stall-fed cows;  and the milk of
animals  so  suffering may contain the germ which
is now regarded as the originator of the mischief.
The  susceptibility of children to tubercular disease
in the abdominal organs is now recognised, and
the death registers show that these diseases, com-
monly called "consumption of the bowels," cause
a large  mortality under the age of five years, but
the public at large has shown but little disposition
                                      13 
194
THE ELEMENTS  OF  HEALTH
to avail itself of the simple precautions which this
knowledge indicates as necessary.
  Milk which has become sour, curdles, and  is no
longer in this state  a fit food for children.  The
souring of the  milk is due to the growth of a bac-
terium in it, which  changes the milk-sugar into
lactic acid, and this acid causes the milk to curdle.
The bacterium is present in the air of dairies and
larders, and sets up this fermentative change the
more rapidly the higher the temperature of the air
and of the milk. Hence the necessity for rapidly cool-
ing milk after it is withdrawn from the cow, and
also for maintaining  dairies and  larders at as low
a temperature as possible in warm weather.
   The curdling of the milk  in the stomach is in
part due to the acid of the gastric juice, and in
part to the presence of a ferment.  In some people
milk  always causes  indigestion.   For  these, the
milk should be curdled before being consumed, so
as to save the stomach the curdling operation which
causes the disagreement.   A  few drops of acetic
acid, or the addition of a little rennet (a prepara-
tion of the gastric mucous membrane of the calf)
to the warmed milk, causes the  milk to separate
into curds (proteids and fat) and whey (milk-sugar,
salts, and water).  By mixing together the  curds
and whey, and adding a little salt and  pepper, a
dish is prepared which, while extremely digestible, 
FOOD                   195
 retains every one of the nourishing constituents of
 the milk.
   When  milk is stored in dairies, most of the
 cream or fat rises to the top and floats on the milk
 within  six hours of the vessel being at rest.  If
 the milk is not thoroughly stirred up before being
 withdrawn from  the vessel, that which is taken off
 the top will contain the bulk of the cream, whilst
 that  withdrawn  from  the  bottom  contains very
 little.
   It is of the very greatest importance that dairies
 or other places used for the reception and storage
 of milk should  be  clean  and  dry, and perfectly
 secure against the entrance of air from drains, soil-
 pipes, cesspools,  and privies.   It should be an in-
 variable rule that there should be no drain under
 a  dairy,  and  no drain  opening, trap,  or gully
 inside it.   Milk is very absorptive of foul gases and
vapours, and  affords  besides an ideal  breeding-
 place for germs of  all descriptions, as it contains
 all the essential requisites for the nourishment of
 animal life.  There can be little  doubt  that nox-
ious germs, which have once gained access to milk,
proceed at once to  grow and multiply, producing
in  the  short space of a few hours countless or-
ganisms for  each individual microbe introduced.
Infected or  contaminated milk is therefore likely
to have its powers  of  doing harm increased for 
196
THE ELEMENTS OF HEALTH
every hour that elapses after it has been delivered.
Although boiling  the milk sterilises  it,  yet this
sterile milk should not be  stored for long, as, if
kept in a close or foul atmosphere, the germs which
gain access to it multiply at a rate even in excess of
that which is usual in unboiled milk.
  It has lately become a custom in the milk trade
for the farmer or dairyman to add small quantities
of antiseptic substances to their milk, to  preserve
it  from  fermentative changes, and  enable stale
milk to be sold as " new."   These antiseptics  are
borax, salicylic acid, and boro-glyceride. Although
the use of such milk preservatives is practically in
many cases a fraud upon the consumer, there is no
evidence  that they  cause, in  the small quantities
only  which  are  necessary, any  damage  to  the
health of the dairyman's customers.
  Butter is made from the cream of milk.   It con-
tains on an average 83 per cent,  of  the most
digestible of all animal fats.   Margarine, oleo-mar-
garine, or butterine is prepared from beef suet or
fat.  It is given the flavour of butter by churning
it with milk, and  the yellow  colour of butter by
the addition  of a colouring  agent—annatto.  This
form of fat is nourishing and digestible, but  less
appetising than  good  fresh  butter.  The  price,
however, should only be half  that of the genuine
article. 
FOOD
197
   In rancid  butter  the fat has  commenced to
 undergo fermentative change, with the production
 of fatty acids, which  render the butter indigestible
 and unsuitable as a  food.  The flavour of rancid
 butter  being  exceedingly disagreeable, it is  not
 often consumed  alone, but  cheap pastry is very
 commonly made from flour and  rancid butter,  and
 stale eggs are used in the manufacture of cakes.
   Light and  well-made pastry  is not indigestible,
 but pastry made " with a heavy hand" is notoriously
 so, probably from the starch cells of the flour being
 in  such a condition  as to resist the action of the
 digestive juices.
   Cheese is another dairy product, being prepared
 from the  curd of milk, which  is obtained by  the
 addition of rennet to milk at a suitable temperature.
 Cheese  is most nutritious, but not very digestible.
 As a general rule,  foods  which contain  a large
 quantity  of nutriment  concentrated  into  a very
 small bulk are not very digestible.   The  cheeses
 which are richest in fat are, as  a rule, the highest
 priced,  although a new industry has lately sprung
 up  of making cheeses rich in fat by  the addition
 of beef  suet, such cheeses being  sold at a  low price.
  Bread in this country is made from wheat flour,
by mixing with  it water, yeast, and a  little salt
until a  consistent dough is formed.   The lump of
dough is placed before a hot fire to allow the yeast 
198
THE ELEMENTS OF HEALTH
to ferment.  In  this fermentation the yeast plant
attacks the starch, some of which is converted into
sugar, and this  again is split up into alcohol and
carbonic acid gas.   The alcohol altogether escapes,
but the carbonic acid gas is prevented from  doing
so by the coherent nature of the dough.  The gas,
in consequence, forms for itself little cellular spaces
in the substance of the dough, which  gives  the
bread its  proper spongy structure.  The loaf is
then placed in the oven and baked by heat.  The
heat destroys any yeast remaining in the loaf, and
thus prevents any possibility of fermentation con-
tinuing in the finished loaf,  which  would  cause
sourness and acidity.
   In aerated bread the loaf is made spongy by the
forcing of specially prepared carbonic  acid  gas
through the dough.
   White  bread  is prepared from  the flour, white
in colour and fine in texture, which results from
the separation from the wheat grain of all its outer
envelopes.   Brown bread  and  whole-meal  bread
are prepared from the whole or nearly whole wheat
grain.  The outer envelopes of the wheat grain are
rich in proteids,  fat, and salts, but being somewhat
hard and horny are  not easily digested.
   It is not yet  settled that whole-meal  bread is
more nourishing than ordinary white bread.  The
poorest classes, indeed, to whom bread is in reality 
FOOD
199
the staff of life, prefer the whitest bread obtainable;
and it may well be  that such  bread contains the
largest amount of assimilable nourishment.  Evi-
dence of want of cleanliness on the part of the
baker is also more readily forthcoming in the white
loaf than in the brown.
  Brown and whole-meal bread, on the other hand,
are useful articles of diet to the wealthier  classes,
on account of  their laxative effect upon the bowels.
The food of this class of people is often so highly
digestible as to leave but little residue in the large
intestines, with the result of  engendering  hard,
scanty,  tenacious fasces, which are  with difficulty
ejected.    The  branny  particles in whole-meal
bread set up a certain amount  of irritation in the
lower intestines, and, increasing  the  intestinal
secretion, promote the proper evacuation of the
bowels.
  There is little or no adulteration of bread at the
present time,  wheat being so  very  cheap.  Even
alum—an adulterant used to cause extra whiteness
in the loaf, and permit the use  of inferior flour—is
but rarely detected now-a-days.  Baking powders,
used to generate carbonic acid gas,  and  cause
dough to rise, are  sometimes made with alum;
but it is doubtful if alum, unless present  in con-
siderable  quantity, is able  to influence health ad-
versely. 
200
THE ELEMENTS OF  HEALTH
   New bread, just  extracted  from  the  oven, is
 usually considered to be less digestible than stale
 bread,  probably  because it crumbles less  in  the
 mouth than stale bread, and so is less subjected to
 the action of  the saliva.  In the stale loaf a con-
 siderable amount of the moisture of the new loaf
 has been lost by evaporation.   It is probably the
 fact that, as baking is carried out in this country,
 the interior of a  large four-pound quartern loaf is
 not completely sterilised by the heat of the oven.
 There is  no evidence, however, of  the  spread of
 infectious disease by means of baked bread.
   Other grains,  generally known as farinaceous
foods, such as barley meal,  rye flour, pea flour,
 bean  flour, oatmeal,  maize, or corn flour, resemble
 wheat  flour as  regards the constituent proteids,
 fats, starches, and salts.  Oatmeal and corn flour
 are richer  in fat than wheat flour, whilst  pea
 and bean flour  are  considerably  richer in  pro-
 teids  than  wheat flour.   This form of proteid,
 however,  is not  so  digestible  as the   proteid
 (gluten) of wheat.   Farinaceous  foods are com-
 paratively but little utilised by the poor  of this
 country;  and  yet they are  cheap, and  can  with
 little  trouble  be  made into most nourishing por-
 ridges, soups, and  puddings,  with  the  addition
 of a little milk.   They  might be  used with  ad-
 vantage to vary the customary diet of  bread, 
FOOD
201
 dripping, or cheap  butter,  and meat of inferior
 quality (see Table, p. 203).
   Rice is more of a starchy food, containing but a
 small  proportion of  proteids—less than half the
 proteids in wheat flour.   The starch is, however,
 extremely digestible when properly cooked.
   Arrowroot,  sago,  and tapioca are  nearly  pure
 starches, and  are valuable  starchy foods.
   Most of the fresh  vegetables, which form part of
 our daily diet, are less useful as foods of the class
 which construct tissue or  supply heat and energy,
 than  as  being the  substances which contain the
 vegetable acids so necessary for the maintenance
 of sound health, and for the prevention of scurvy.
 Such  vegetables as cabbage, cauliflower, spinach,
 sprouts,  turnips, and carrots contain from  80 to
 90 per cent, of water, and  less than 10 per cent, of
 starch.  Besides  their  anti-scorbutic properties,
 they are also most useful in increasing the bulk of
 the fasces, inasmuch as they contain cellulose or
 woody fibre,  which is totally  indigestible.  The
 fasces  consist of   indigestible  and undigested
 matters,  and water;  and with a purely animal diet
 they are so hard, scanty,  and tenacious, as  to be
ejected with difficulty from the bowel.  The addi-
tion of these fresh vegetables tends to  make the
 motions  more copious and more watery (what is
termed loose), with the  result that they  more 
202
THE ELEMENTS  OF HEALTH
easily pass through the large bowel to be eva-
cuated.
  Potatoes are valuable anti-scorbutics,  and con-
taining  21 per cent, of starch, they may be reck-
oned as valuable starchy foods.  The juice  of the
potato is distinctly acid from  the presence  of the
vegetable acids.  When potatoes  are steamed  in
their skins there is not so great a loss of salts as
when they are boiled  after being  peeled.   Conse-
quently in the  former state  they are  somewhat
more nutritious.
  Fresh fruits of  various  kinds,  like fresh vege-
tables, are valuable food adjuncts  for very much
the same reasons.   Although  the  vegetable acids
are essential to healthy living, too great a quantity
of them should not be taken.  The introduction of
an  excessive amount of acid  substances into  the
stomach causes acidity and indigestion.  As is well
known, acid fruits  should be eaten in strict mode-
ration.
  The peel, skin, or rind of most fruits  should be
rejected—firstly,  because  these  outer  envelopes
contain much indigestible  cellulose, and secondly,
to avoid the risk  of  introducing into the stomach
what has been handled by often unclean hands. It
is desirable also that  all kinds of  fresh vegetables
should be cooked, and not eaten raw.  Most of them
are not digestible unless  cooked, but  it  is  the 
FOOD
203
custom to  eat lettuce, mustard and cress, celery,
and watercress  uncooked.   Inasmuch  as these
vegetables are sometimes manured with sewage, it
is certainly wise  to wash them very thoroughly in
clean water before sending them to the table, even
if it is not  considered necessary to cook them.
  It is doubtful  if tinned vegetables contain the
antiscorbutic  properties of freshly-gathered pro-
duce.  Tinned peas are not uncommonly coloured
green  by means  of a  salt of  copper, which is not,
however, usually present in  sufficient  quantity to
cause serious illness.
In 100 parts.
Wheat flour
Barley meal
Rye flour
Pea flour
Bean flour
Oatmeal
Maize
Arrowroot
Potatoes
Cabbage
Water.
 150
 11-3
 13-5
 114
 10-3
 150
 135
 154
 74-0
 91-0
Proteids.	Fats.	Starches.
. n-o .	2-0	70-3 .
. 127 .	2-0	71-0 .
. 131	2-0	69-3 .
. 25-2	2-0	572 .
. 23-2	. 2-1	. 59-4 .
. 126	5-6	63-0 .
. 100	. 6-7	64-5 .
08	—	83-3 .
20	0-2	21-0 .
1-8	0-5	5-8 .
Salts.
1-7
3-0
2-1
2-9
33
3-0
1-4
03
1-0
0-7
  Lemon juice,  lime juice, and vinegar are chiefly
valuable as antiscorbutics.
  The condiments are  the  food-accessories which
are added to food as flavouring agents.  The prin-
cipal of these are mustard, pepper, onions, cloves,
cinnamon,   nutmeg,  caraway,  cardamoms,  &c. 
204         THE ELEMENTS OF HEALTH
Vinegar and common salt  are also condiments, as
well as valuable  foods.  Common salt  or  sodium
chloride is taken at every meal, and  is  essentially
a food, for all classes of food are deficient in this
substance, which is necessary for the wants of the
body.
  The function of condiments is to  stimulate the
flow of the digestive juices, and also  the peris-
taltic action of  the stomach and bowels, by which
the food is churned up,  intimately mixed with the
digestive  fluids, and borne along from one part of
the alimentary tract to another.  They also  contain
an antiseptic substance which, whilst it may have
the effect of retarding  digestion, certainly in the
case of a large mixed  meal  tends to prevent fer-
mentative decomposition of food  and consequent
dyspepsia.  Oil of mustard  is  a powerful  anti-
septic.
  Alcoholic  Beverages.—Whilst it is a matter of
general agreement that  the consumption of  alco-
holic drinks between meals, as a regular practice,
is productive of nothing but  harm to the  system,
there is no such agreement as to the  dietetic value
or worthlessness of alcoholic beverages taken with
meals.
  To the credit of such alcoholic beverages as beers
and wines it may be said—(1) That the amount of
alcohol they contain is not large—beers  contain 
FOOD
205
from  3  t6  7 per cent, of alcohol, wines from 10 to
25 per  cent.  (2)  Beers and wines have some of
the properties of  foods—they  contain sugar  and
starchy matters, mineral salts, and vegetable acids.
(3)  If taken in very moderate quantities they pro-
mote  the flow of  the digestive juices, partly by
reason of their contained alcohol, partly from the
presence of compound aromatic ethers  and bitter
principles,  which act as  stomachic tonics.
  On the  other hand, both  beers  and wines un-
doubtedly  retard  digestion, and such retardation
if habitual is probably deleterious.  If, however,
the meal is very large, the retardation is probably
not injurious, as giving  more time for the thorough
completion of the  digestive process; and the alco-
holic  liquid in the  stomach checks any fermentative
change  which might otherwise ensue as a conse-
quence  of undue retention of food in the stomach.
  Excess of stimulants, however, at  meals is un-
doubtedly  injurious, and inasmuch as no rule can
be laid  down as to the exact amount which should
not be  exceeded, individuals differing so  widely,
everyone should from experience form a rule for
himself or  herself.  It may certainly be stated  that
if digestion and appetite are good without recourse
to stimulants at meals, it is folly to initiate a prac-
tice which  is unproductive of any advantage, and
is at the same time a source of expense.  There are, 
206
THE ELEMENTS OF  HEALTH
 however,  people  to  whom some form  of  alcohol
 with their chief meals  appears to  be more or less
 of a necessity.  Without it, digestion is inefficient,
 and bodily health is not  maintained.
   Malt Liquors are, as a rule, not to be recom-
 mended for  persons of weak digestion.  For the
 labouring man, beer in moderation is not harmful,
 and may provide him with  such  substances as
 mineral salts and vegetable acids, which his diet
 is otherwise deficient in.  To  a  man  in  active
 exercise also, beer in moderation does not tend to
 interfere  with  the elimination  of effete matters
 from the blood, and the consequent production of
 liver disease  and  gout, as  is frequently observed in
 beer drinkers  of sedentary habits.  Lager beer,
 as prepared  in Germany  and Austria,  for home
 consumption  and not  for  export,  is considerably
 lighter  and  less  heady  than  English  beer.  It
 contains somewhat less alcohol, and much less free
 acid, which  is so frequently  the cause of acid
 dyspepsia.
   Wine is better for a weak  stomach than beer,
but a great deal depends  upon the  choice of  the
 wine.  Many of the natural wines are so fortified
and  sophisticated  for  the English market, that
 although  wholesome  enough in  their  natural
 condition, the  " finished" article  is to  be abso-
lutely shunned.  The cheap French clarets, ports, 
FOOD
207
sherries, and Marsala are  fortified with spirit, and
doctored  with flavouring  agents,  to  an extent
sufficient to render them very far from wholesome
beverages.   Port, sherry, Maderia, and  Marsala
contain from 15 to 20 per cent, of alcohol; cham-
pagne about 10 per cent.; and clarets, hocks, and
Burgundies from 8 to 12 per cent, of alcohol.
  All  wines, like  beers,  are acid,  this  acidity
being  chiefly due to the presence of tartaric acid.
Very acid wines should be avoided, as liable to
produce dyspepsia;  as also  should  very   new
wines, which  contain  an  excess of  astringent
matter in the form of tannin.  In a wine matured
by  keeping, some of the tannin  and colouring
matter has been deposited, and some of the volatile
acid has escaped.
  As a general rule it may be said that the most
wholesome  wines are  light, natural  vintages,
which contain from 7 to  10 per  cent, of alcohol,
and which are not too acid.  Such wines are pro-
duced in Germany and Italy as well as in France.
Effervescing wines like champagnes, which con-
tain much sugar,  and are very sweet, are distinctly
less wholesome than the " drier " wines.  It  must
be understood  that " dryness " is  no evidence of
absence of sophistication.   " Dry " sherry is very
frequently  the result of the manipulation of the
merchant, and not the natural quality of the wine. 
 208        THE ELEMENTS OF HEALTH
   Spirits contain much more alcohol than beer or
 wine.   The quantity of alcohol is  seldom under
 35 or 40 per  cent, in brandy,  whisky, or rum.
 Spirits should always be consumed with  at least
 4  times their  volume in water, in order to avoid
 the  injurious  action of  concentrated alcoholic
 liquids upon  the  delicate linings of  the mouth,
 gullet, and stomach.  Spirits should not be drunk
 until well mellowed by keeping.  During the mel-
 lowing process, fusel oil—the common name  for
 the  higher  series of alcohols,—and also furfurol
 —an aromatic substance,—are given off, these being
 substances which are not only highly intoxicating,
 but  also very  injurious  to the digestive  organs.
 A properly matured  spirit, such as old whisky,
 adequately diluted  with  water, is the most whole-
 some form of  alcoholic stimulant for a great many
 people, to whom  any acid  in their  beverage is
 injurious.  Spirits  are practically free from those
 vegetable acids  which  are  characteristic of all
 beers and wines.
   Tea,  coffee,  and  cocoa  contain alkaloidal sub-
 stances which  stimulate the nervous system,  in-
 crease the pulse and the action of  the  skin, and
 generally act  as restoratives in fatigue.   Tea and
coffee taken hot are valuable both in very hot and
very cold weather.  The  heat of the  infusion gives
warmth to the body in cold weather, and increases 
FOOD
209
the action of the skin, causing more heat to be lost
from the surface in hot weather.
  Both tea and coffee retard digestion, and are not
suitable beverages to be taken at meal-times.  In
the early morning, or for breakfast, a cup of hot
tea or coffee is no doubt desirable,  the  nervous
system so early in the day being  all the better for
stimulating; but to take tea at every meal of the
day, as is so often done, is  to  retard digestion
without any compensating benefit.   The abuse of
tea  is a very frequent  cause  of dyspepsia, and
leads also often to nervous depression and sleep-
lessness.
  In making tea, it is  advisable to  prevent too
much of the tannin present in the  leaves  passing
into the infusion.  Tea  which has  "stood" for
over five minutes becomes unduly astringent, and
this astringency  interferes  with digestion.   Tea
should  be  made with boiling water, but  after
standing for three or four minutes  the  infusion
should be poured out into another vessel.
  Coffee is  less astringent than  tea, and  in  some
people it has an irritating effect  upon the bowels,
causing diarrhoea.  Good coffee is more difficult to
make than good tea.  The berries  must be  fresh
roasted and ground, and the  infusion with hot
water must  not be  boiled, otherwise the aroma is
lost.   Chicory is merely an adulterant of coffee,
                                      14 
210         THE  ELEMENTS OF HEALTH
and  has none of its stimulating and refreshing
effects.
  Neither strong tea nor coffee  should be  taken
late at night, as they may cause sleeplessness.
  Cocoa is much less  of a stimulant than tea or
coffee, and is more of a food, containing nearly
50 per cent, of oil  (cocoa butter).   As this fat or
oil is not very digestible, cocoa is generally sold
now  with  at least half its  oil abstracted, and
mixed with  arrowroot.   In this  form  cocoa is
certainly more digestible than in its crude state.
  Mineral Waters are either derived from natural
springs,  the  water of  which contains  gases or
mineral salts in solution ; or they are manufactured
by forcing carbonic acid gas into distilled water, or
into  river, spring, or well-water,  and dissolving
small quantities of  mineral salts in them.
  These mineral waters  serve a useful purpose as
dietetic adjuncts, the carbonic acid stimulating the
digestive organs, and the  mineral  salts also being
useful, unless  present  in  too large  an  amount.
A beverage  containing an excessive amount  of
common salt, as is well known, increases thirst and
does not allay it; and some of the  natural springs
certainly err on the side of excess, regarding their
waters as beverages and not as medicines.
  Too much  reliance should not be placed on the
purity of the  artificially  aerated  waters.   These 
FOOD
211
may have been derived from sources open to con-
tamination, such as polluted streams and shallow
wells.  It  also  frequently  happens  that these
waters contain metallic lead in dangerous quanti-
ties.  The lead is dissolved out of lead pipes or
lead apparatus  used in the manufacture of the
carbonic acid.  It ought  to be  made  compulsory
for all carbonic acid generators  to be  constructed
of silver or to be silver lined, lead pipes and appa-
ratus being prohibited. 
212         THF ELEMENTS OF HEALTH
                CHAPTER IX

               PHYSICAL EXERCISE
Effects of exercise on the bodily organs—Rest—Growth of the
   body—Kinds  of  exercise:  Walking, Running, Jumping,
   Rowing, Games, Feats of strength—Training or preparation.
  By physical exercise is meant the regulated use
of some or all of the muscles of the body.
  The importance of regular exercise will be best
understood from a description of the effects it pro-
duces on the chief organs of the body.
  (1) The Heart and Circulation.—The action of
the heart is increased both in force and frequency;
the blood circulates  more quickly throughout the
body.   This result is assisted by the muscular con-
tractions pressing the blood in the veins  onwards
towards the heart;  this venous blood being  also
aided in its passage to the heart by the deep inspira-
tions excited by the exercise.
  (2) The Lungs.—The inspirations and  expira-
tions are increased  in frequency and volume; the
amounts of air inspired and expired in a given time
are very much larger than if the body  was at rest.
In  consequence the blood  is supplied  from the 
PHYSICAL EXERCISE           213
inspired air with a much larger amount of oxygen,
and gives off a corresponding excess of carbonic
acid and water to the expired air.
   (3) The Voluntary Muscles.—The muscles which
are under the control of the will are brought more
or less into play.   The  accelerated  circulation
brings through the arteries a  highly  oxygenated
blood-supply to the  muscles, containing abundant
material for the repair of old tissue, and  for the
construction of new;  whilst the rapid venous flow
carries away the waste products of muscular action
to the various excretory organs.   The play of the
muscles is essentially a rhythmic contraction, by
which the  muscles  are shortened, the points  of
attachment and insertion of each end of the muscle
being brought closer together ; and this is followed
within a  short space of time  by relaxation.  In
most exercises certain groups of muscles are con-
tracting,  whilst other groups  are relaxing.
   (4) The Skin.—The circulation of blood through
the vessels  of  the skin, lying close beneath the
surface,  is  much more rapid.  The radiation  of
heat from the surface of the body  is thereby much
increased; and the excess  of heat, which  is pro-
duced in the  body by the rapid combustion  of
tissue, is  allowed  to  escape.   If  the exercise  is
severe, or the air temperature is high, water  is
excreted from the blood by the sweat  glands  in 
214         THE ELEMENTS OF HEALTH
the form of sweat, which appears on  the  surface,
and being quickly evaporated, tends immensely to
cool the body by reason of  the abstraction of the
large quantity of heat necessary to evaporate the
water into steam.   A very important  function
of the skin is this regulation of the body tempera-
ture,  and  the prevention  of any  rise  above the
normal average—98*4° F.
   In consequence of the increased  supply  of blood
to the  voluntary  muscles  and to the skin, the
tendency towards partial stagnation of the blood in
the large abdominal organs, such as the liver and
spleen, is overcome; and the congestion  of  these
organs, so  commonly met with in those who lead a
very sedentary life, is prevented.  Exercise involv-
ing the  abdominal  muscles is also  very  often
effective in overcoming  a tendency  to  habitual
constipation.
   Exercise should be succeeded by rest, to allow the
muscles and nerves to get rid of the waste  products
of their  action,  which tend to accumulate during
exertion; and in order that repair of wasted tis-
sues,  and formation of new tissues,  may go on.
Without suitable  periods  of rest, the  nerves and
muscles become exhausted, and the muscular con-
tractions become gradually enfeebled.
  It is thus seen that properly regulated  physical
exercise must  cause increased appetite  and thirst, 
PHYSICAL EXERCISE
215
and more food and drink to be consumed.  The
digestive organs  are  increased in efficiency, and
all parts of the body benefit.
  The muscles themselves grow larger and harder,
and in consequence more powerful.  Muscles which
are unexercised are soft, weak, and flabby, and
incapable of prolonged or arduous exertion.
  Nearly all kinds  of physical exercise, indulged
in in  moderation, are  distinctly health-giving.   If
undertaken  in  the  open air, the benefit to health
is always in advance of  that obtained by exercise
within  doors.   There is  even a greater necessity
for pure air during exertion, than when the body
is at rest.
  Of  the various kinds  of  exercise, walking or
pedestrian  exercise is by far the  most common,
being suited for individuals of all  ages,  and of
every  degree  of  development.   Whilst  mainly
exercising  the muscles of the legs and thighs, it
also brings  into play the  muscles  of  the loins,
back, and abdomen in order to keep the body in
an erect position.  In walking the body should be
erect, the chest thrown out, the head thrown back,
and  the stride long and elastic, the legs being
well swung out from the hips, and straightened as
soon as  the feet are planted on the  ground, so as
to secure the full length of the stride.   The act of
walking with bent head, stooping  shoulders, con- 
216
THE ELEMENTS OF  HEALTH
tracted chest,  and  over-bent  knees  is  neither
graceful nor healthful,  and is in the long  run
more tiring  than walking in the correct attitude.
Walking across country, as for shooting or playing
golf, is  preferable to walking on the high roads,
the ground being  softer  and  more  elastic,  the
motion therefore more various and less monotonous,
whilst there is at the same time an object constantly
in view, which makes fatigue less apparent.
  Running is an excellent exercise for the young
and  robust,  but   should  be   moderately   and
sparingly indulged  in after the age of thirty.  If
it cause much panting, extreme breathlessness, a
sense of oppression on the chest, a feeling of faint-
ness, palpitation of the heart, and subsequent pain
over the cardiac region, the exercise is too severe,
and  its continuance is likely to do much harm.
These  symptoms are frequently experienced  by
men of middle  age who, without previous prepa-
ration of any kind, attempt unwonted  exertion in
running.  The breathlessness is due to an excess of
carbonic acid  in the venous  blood, derived from
muscles out of condition and containing too large
an amount of combustible matter.  The lungs are
unable to get rid of this  carbonic acid, as soon as
it is formed, with the result that they become en-
gorged  with venous blood, expiration is rendered
difficult, and the train of  symptoms  enumerated 
PHYSICAL EXERCISE
217
 above are  produced.   Running for  races  should
 never be  attempted without previous systematic
 training.
   Jumping is not an exercise much pursued except
 for the purposes of competition ; but skipping with
 a rope is a form of jumping, and of this exercise it
 may  be said that  it is one of the very best for
 growing children.  It brings into play nearly every
 muscle of the body, without putting  undue strain
 upon any particular group.
   Of rowing it may be said that there is no form
 of exercise that has so marked an effect in develop-
 ing the chest if only the rower or sculler is properly
 taught.  There is  probably no form  of exercise
 which requires such careful supervision and tuition,
 if the beginner is to acquire the proper style, with-
 out which nearly all the benefit  of the  exercise is
 lost.  In both  rowing  and  sculling, if carefully
 performed, nearly every muscle  of the body is  ac-
 tuated, more  especially the  muscles  of the chest,
 back, abdomen, and loins.  To row with bent head,
 stooping back,  and contracted chest,  whilst the
 muscles of the arms are allowed to do all the work,
 is to cultivate  a  style which  quickly develops
 fatigue, and fails to exercise properly the great
 muscles of the trunk, or increase the respiratory
and vital powers.  It is wonderful how greatly the
chest  may  be developed in  young men  by sys- 
218
THE ELEMENTS OF HEALTH
tematic training in rowing.  The capacity of  the
thorax is increased, and  the  individual gains in
breathing power, whilst the muscles of the chest,
back, and shoulders are greatly strengthened.
  Nothing but praise can be given  to such exer-
cises  as  skating, swimming, riding  on horseback,
or to such  outdoor games as cricket, lawn tennis,
football, &c.   Boxing,  fencing,  and  gymnastic
exercises are specially useful, under proper super-
vision  and training, for developing muscles and
senses alike.
  With the exception perhaps of football,  there is
no reason  why girls and women, as well  as boys
and  men, should not participate in  all the above-
mentioned exercises, games, and sports.  It is cer-
tainly true that the female body cannot, any more
than  the male, attain its perfection of  graceful
development without recourse to systematised exer-
cises ; and it is a matter for congratulation that
this  is a truth to which  the  public mind is very
rapidly awakening.
  Mr. Treves, F.R.C.S., in his excellent article* on
" Physical Education " in A Treatise bn  Hygiene
and Public Health (J. & A. Churchill), is of opinion
that exercises or games in which jumping takes a
prominent position are not well suited for girls and
women, and  is also  inclined  to regard  cycling as
         * Published also separately, price 2s. 6d. 
                PHYSICAL EXERCISE           219
 one of those forms of  exercise which are best left
 to the male sex, the exercise involving too exclu-
 sively the use of the lower limbs and of the muscles
 about the pelvis to be an ideally healthy one for
 women, whilst the  pressure caused by the saddle
 on the perineum is also undesirable.
   There can be no doubt whatever that for ordi-
 nary individuals, and during the period of growth,
 the most excellent exercises are the gentle  ones,
 where no strain is placed upon the organs of respi-
 ration and circulation.  Exercises of strength, and
 those involving speed  or rapid movement, are best
 left to youths and young men who have undergone
 preparation and training.
   Those exercises, too, which, like feats of strength,
 require sustained effort, are best avoided by the un-
 prepared individual.   In the making of the effort
 a deep breath is taken, and the chest is filled with
 air, and the  glottis or  valve guarding the opening
 at the top of the windpipe is then closed, so as to
 keep  the lungs  expanded.   The thorax then be-
 comes a  fixed base for the  shoulder and chest
 muscles to actuate the arms.   Respiration is thus
 brought to a standstill, and the right side of the
 heart becomes over-distended  with blood.  Such
 accidents as hernia, rupture  of blood-vessels, and
 strains of muscles  and ligaments,  are  most apt to
occur during these sustained efforts. 
220
THE ELEMENTS OF HEALTH
  The subject of " training " is hardly one requir-
ing discussion.   In  former times very senseless
practices and restrictions were imposed upon those
who placed themselves in the hands of professional
trainers; but these  follies  are now universally
abandoned in favour of training founded upon rules
consonant with physiology and common sense.
  For those who wish to increase their  athletic
powers without submitting themselves to profes-
sional training, it will be wise to keep in remem-
brance the following simple rules :—(1) Commence
gradually, and  progress by very easy stages to
more prolonged or more arduous exercises.  (2)
Avoid any strain or very violent exertion until the
body is sufficiently  prepared,  and  always  cease
exercise as  soon as fatigue is noticeable.  (3) Be
warmly clad after  exercise, and avoid chills.  (4)
Take your  accustomed food at  regular meals,  and
be  very  moderate in the use  of alcoholic drinks
and tobacco; but do not imagine that any good can
result  from  eating  large quantities  of  half-raw
meat, and reducing  very largely the  consumption
of starchy foods.   (5) Drink when thirsty; small
quantities of fluid at  a time are far more beneficial
than long draughts  at great intervals.   Thirst is
sometimes caused  by dryness of the mouth,  and
not by any  demand of the tissues for water.  This
form of thirst may be relieved very often, without 
               PHYSICAL EXERCISE           221
swallowing any liquid, by simply washing out the
mouth with water.  In walking and climbing hills
try to breathe through the nose, keeping the mouth
shut,  and regulate the pace so that this can be
done without discomfort.  Breathing through the
mouth induces dryness and  thirst.   (6)  Avoid
garments  which  constrict the  neck, chest, and
abdomen, and wear clothes which allow free play
to all the muscles of the body.  (7)  Allow plenty
of time for  sleep—seven hours  to  nine  hours,
according to the  needs of the  individual.  Re-
cuperation of the  body is most  largely carried on
during the hours of sleep. 
222          THE ELEMENTS  OF HEALTH
                  CHAPTER X

                     CLOTHING
Use of clothing—Amount and  character  of clothing—Under-
    clothing and chills—Outdoor clothes—Wet feet, damp beds,
    and " draughts "—Constricting garments : Hats, belts, stays,
    garters, and boots—Clothing in childhood and in old age—
    Cleanliness of clothing.

  In  so changeable a climate as that of England,
the subject  of  clothing must always  be one of
great hygienic importance.
  The chief  use  of clothing,  hygienically  consi-
dered, is to maintain the temperature of the body
at its normal level.   Whilst it  is necessary,  there-
fore,  to have garments to protect the body  and
limbs from the effects of heat, cold,  and moisture,
these must be so arranged as to allow the  greatest
possible freedom to all muscular movements. Any
constriction or  compression of  a limb or of the
body  retards  muscular  action, interferes with the
circulation of the blood, and in the case of  abdo-
minal compression is liable to  displace or  injure
underlying organs.
  The amount and character of the clothing that 
CLOTHING
223
should be  worn must 'depend chiefly  upon the
weather and the season of the year, upon whether
the body is to remain passive or engaged in active
exercise, and upon other considerations  of a simi-
lar character.  It is  not, therefore, possible to lay
down any precise rules of general utility, except
perhaps as regards the underclothing—that which
is  worn next  the skin—upon which subject  there
is  a fairly general consensus  of opinion amongst
medical men.
   As a general rule some form of woollen garment
should be worn next the  skin, because woven wool
is  a very bad conductor of heat, and whilst it is a
good absorbent  of moisture, it gives the moisture
off very slowly.  The first quality—the bad con-
duction of  heat—is  due  partly to  the wool  fibres
themselves ; but perhaps in a greater degree  to the
fact that a quantity of air—the worst conductor of
heat known—is  entangled  in  the meshes of  the
woollen garment.  A woollen  garment,  therefore,
tends to keep up the temperature  of the body by
preventing the radiation of heat from the surface
of the skin.  It  also prevents chills when the sur-
face of the body is moist from perspiration, as the
wool  absorbs  and holds the moisture, and only
evaporates  it slowly.
   Chills, as is well known, are especially apt to be
taken  when the  body is subjected  to  cold when 
224
THE ELEMENTS  OF HEALTH
perspiring, either  from the effects of exercise, or
from staying in  an overheated  atmosphere  and
then passing out into the cold outer air.   The eva-
poration of  the water on the skin absorbs much
heat from the  body,  and if this evaporation  is
suddenly checked a chill  is produced—a nervous
phenomenon, subsequently manifesting itself usu-
ally in some inflammatory affection.   An under-
garment of thin calico (cotton) or linen becomes
soaked and  clammy from  perspiration,  which  is
rapidly evaporated,  causing a chill to the surface
of the body—just the reverse, therefore, of what
happens with a woollen fabric.  If linen or cotton
are worn next the skin owing  to flannel causing
irritation, the material should be  loosely  woven so
as to intercept as much air as possible in its meshes,
in order to render it  a bad conductor of heat.  The
"cellular" cotton underclothing  appears to fulfil
this  condition.
   Silk comes next to wool as a material for under-
clothing, and  is  superior  to cotton  and linen,
having better hygroscopic (i. e. moisture absorbing)
qualities than either  of the latter.   It  is, however
too expensive for very general wear.
  After  severe  exercise, it  is  not wise to trust
entirely to the chill-resisting qualities of  a flannel
shirt.  Extra clothing should always be assumed,
more especially if the exercise is succeeded  by 
CLOTHING
225
 complete rest.  Even athletes in the most perfect
 training are very susceptible to chill when at rest
 after active exertion.
   In cold weather out-door clothes should be thick,
 dark,  and  composed  largely of  cloth, i. e.  some
 form of woven wool.  The coldest and most trying
 weather  is  that  experienced when a cold,  dry,
 north-east  wind prevails.   The wind  causes the
 cold air  to penetrate through clothing which  is
 not of the thickest and closest  material, and the
 heated air  around the body is swept  away to be
 replaced  by cold air.   The relative dryness of the
 air also causes rapid evaporation of moisture from
 the body.   These  two  causes   acting together
 cause   sudden  losses  of heat, which result in
 chills,  unless the  clothing  affords proper  pro-
 tection.
   Furs, and thick shaggy woollen materials, such
 as Scotch tweeds and  Irish friezes, afford the best
 protection against  cold  winds. Waterproofs  are
 also valuable, being  impermeable  to  both wind
 and rain,  but should  not be worn  during active
 exercise, as they favour the accumulation of per-
 spiration, owing to their want of porosity, and the
body when soaked with perspiration is very apt to
be suddenly chilled.  Simply as a protection from
rain, waterproofs are far superior to heavy, shaggy,
woollen overcoats, as  the latter  become  soaked
                                      15 
226
THE ELEMENTS OF HEALTH
with water, and in that state  are  not only very
heavy, but also difficult to dry.
  In hot weather the garments may be light, white
in colour, and  thin.  White clothes are the least
absorbent of the heat of the sun's rays. Although
it is not desirable  to have  the body warmly clad
in hot weather, chills should be provided against,
as a sudden check  to perspiration is no less to be
dreaded in  hot than in cold weather.  In some
hot countries  a cloak  is carried,  to  be  thrown
around the wearer  when he passes from sunlight
into shadow, and at the approach  of  sunset.  In
India the abdomen is usually swathed in  flannel,
to avoid the chills, which in tropical countries seem
especially liable to  set up diarrhoea and dysentery.
  Of all forms of indiscretion, the practice  of " sit-
ting with wet feet" is perhaps that  which most
easily conduces to " catching cold."  Although the
surface of the body which in this  case is chilled
is comparatively trivial as  compared with  that of
the trunk, yet there can be no doubt a very pro-
found  nervous depression  results  in  very  many
people.  So long as exercise is  maintained, clothes
wet from rain or perspiration, and boots sodden
with water, do no harm; but thefailure, or inability,
to change into dry garments, when the body is at
rest, is for the majority of people to incur very
grave  risk of future ill.  A very dangerous form 
CLOTHING
227
of " chilled feet " is that produced by walking in
defective boots through snow which has been con-
verted into slush by means of salt—a most inde-
fensible  practice  still largely pursued in London
and other cities.   The  salt and snow create a
freezing mixture,  many degrees  below freezing-
point, and this liquid—colder than ice—chills the
feet of passengers, especially of the badly-shod, to
an extent which  is  undoubtedly highly injurious
to health.
   Sleeping in damp beds is another frequent source
of mischief.  During the hours of sleep the vital
powers are diminished, and the  tendency to chill,
arising from the abstraction of the bodily heat to
evaporate the moisture  in damp sheets,  is very
much enhanced.   No one  should ever  sleep be-
tween  damp sheets.  It is a safe rule to discard
the sheets, and, enveloped in a dressing  gown or
the day clothes, to seek repose between the blankets.
   Colds are  frequently  caught  from "sitting in
draughts."   Draughts should, wherever possible,
be avoided ; but if unavoidable, as may be the case
in railway travelling, it is always well to remember
that less harm is likely to result if a draught is
faced, than if the back is turned  towards it.   The
back is  decidedly sensitive to cold, perhaps more
so than the chest; yet the chest-protectors so com-
monly  worn  by a  certain  class, who suffer from 
228
THE ELEMENTS OF HEALTH
colds and chest affections, are  nearly always pro-
tectors of the chest, and  not of the back.  It is
seldom  wise  to  clothe the body unequally in this
manner.  Certainly the   woollen  comforter  so
usually  worn around the neck is more likely to in-
duce throat delicacy and  liability to chill, than to
have any useful effect.
  The importance of not compressing the limbs or
body by constricting garments has been already
alluded to. The common sites of constriction are—
(1)  around the scalp by a heavy, hard,  and  tight-
fitting hat; (2) around the  neck  by too tight a
collar;  (3)  around the waist  by  a tight belt in
males, and by tightly-laced stays in females; (4)
around  the knees, either above or below the knee-
joints, by garters; (5) compression of the toes by
the use  of ill-fitting boots.
  The  compression of the  scalp by a hard  hat
interferes with the circulation of the blood through
the  blood-vessels, and may  cause  neuralgia  or
baldness, the  nutrition of the hair-follicles  being
affected by  the  disordered circulation.   The con-
striction of the neck by a  tight collar  may cause
venous congestion (lividity) of the face and head,
especially during exertion.
  The compression of the waist by a belt interferes
with the action of the diaphragm—the  most im-
portant muscle of respiration—and tends to favour 
CLOTHING
229
the production of hernia.   Tight  lacing is well
known as a cause  of dyspepsia in women, from its
undoubted effect, when carried  to an  extreme, in
producing displacement of the  stomach and  other
abdominal  organs.   In moderation  there  is no
doubt something to be said in favour of the use of
stays, which give support to the figure, and afford
attachment to the more weighty articles of clothing;
but for girls and very young women,  their use is
to be deprecated as causing interference with the
proper development of the  chest organs.
   The use of garters tends to obstruct the venous
circulation in the legs, and to favour the production
of varicose veins.
   Ill-fitting boots,  when continuously  worn,  cause
permanent disfigurement of the feet, not to men-
tion such  sources of discomfort  as corns and
bunions.
   The natural shape of the foot is that of an open
fan, the toes representing the expanded part of the
fan.  The boot, therefore, should  be fan-shaped,
the inner side of the fan being more prolonged than
the outer side, and  the inner line of the sole from
the extremity of the  big toe to the instep being
straight  and pointed inwards, and not curved out
from the ball of the big toe as is  the case  with
all boots and shoes having pointed toes.  In some
cases of extreme deformity, from the use of narrow- 
230
THE ELEMENTS  OF  HEALTH
pointed boots, the toes are made to  overlap, and
locomotion becomes difficult  and painful.
  It is very  important that  the delicate feet of
children  should not be compressed in ill-fitting,
badly-designed boots.   Deformities  of the  feet,
which  cause  so much  trouble  in adult life, are
usually acquired in  childhood.  The boots should
be easy, so as to allow of free movements of the
toes, without which proper muscular development
of foot and leg cannot take place;  and the soles
should be pliable, not stiff, so as to allow of the
natural bending of the foot across the line of joints
forming the  ball of the foot, without which loco-
motion is never  easy, free, and graceful.  High
heels are  a  mistake.   They tend to  throw the
weight of the body too far forwards, placing an
undue  strain upon  certain groups of  muscles in
order to  maintain the balance,  whilst other im-
portant groups are not sufficiently exercised.  A
firm, even tread  cannot be  expected  when high
heels are worn.
  Garments which fit very tight  not only hamper
muscular  movement, but  are generally less warm
and comfortable,  from the fact that  there is not a
sufficient layer of non-conducting air  around the
skin to maintain an equable body temperature,
and to facilitate the steady transpiration of skin
moisture.   Tight garments,  which  cling  to the 
CLOTHING
231
skin, impede the ventilation of the skin  surface,
upon which comfort so  largely depends,  and be-
come more rapidly soaked with perspiration  than
does loose clothing.
  This is no doubt the reason why hats, which do
not rest upon the head  except  at  the  brim, and
afford an air space over the  greater part of the
scalp, are so popular with the male  sex.
  At the two extremes of life—in early childhood
and in old age—warmth of clothing is most essen-
tial.  Little children are more susceptible to cold
than adults, —firstly, because the circulation of blood
is more rapid, and in consequence, more blood
being passed through the superficial skin vessels
in  a given time, more heat  is radiated from the
surface; and secondly, because  the surface of a
child's  body is  considerably larger in  proportion
to its bulk or contents than  is that of the adult.
The larger the  surface of a warm body in propor-
tion to its bulk, the greater is  the rapidity with
which heat is lost from it.   From such considera-
tions as these it will be understood how  senseless
and injurious is the fashion of allowing little chil-
dren to run about with bare arms and legs.
   At the other extreme of life, if the body becomes
chilled  its restoration to a normal temperature is
often slow, and the activity of the vital organs
becomes dangerously depressed.  The  feeble and 
232          THE ELEMENTS OF HEALTH
languid circulation and heat-producing powers of
old age are manifested by habitually cold extre-
mities, and by a tendency to lividity of the face
during exposure to cold.
  Articles of underclothing are not very commonly
at the present time coloured with dyes containing
arsenical or other poisonous pigments.  It is worth
noting that sores and ulcers on the feet have  been
traced to the use of stockings containing arsenical
colours.
  The cleanliness of  clothing is not a matter  upon
which it is necessary to dilate at any length.  The
garments next the skin absorb perspiration at all
times, but especially in hot weather,  and likewise
become the receptacles for much of the epidermic
debris, or scurf, which is continually being  shed
from the skin's surface.  These matters are nitro-
genous and liable to  decompose—a truth which is
at once apparent from the odour given off by an
undergarment which has been worn too long.
  A garment exhaling foul odours is not only un-
pleasant to  the senses of the wearer, but is dis-
gusting to  his neighbours, and  renders  more
unsupportable  the misery of the  close crowding
together of human beings.
  Cotton and linen articles can be readily  washed
and purified, but in the case of woollen garments,
which  are the most  absorbent of foul matters, 
CLOTHING
233
washing with soap in hot water, and wringing out,
deteriorates the fabric.  The hardening, shrinkage,
and loss of elasticity of woollen goods washed by
the ordinary methods is well known.  The flannel
shirt that goes to the  laundry a size too large for
the wearer, very frequently returns three sizes too
small.   Woollen  goods should be washed in soft,
tepid water, with mild  soap, and without soda, and
should  not be wrung.  Much of the impurity in
wool may be got rid of by long exposure to air and
sunlight; but  some soap  is  required to remove
effectually the dirty grease which is lodged in them
by absorption of  the sebaceous secretion from the
glands at the roots of the hair-follicles. 
234
THE ELEMENTS OF HEALTH
                 CHAPTER XI

   THE CARE OP THE SKIN, TEETH, AND BOWELS
The skin as an excretory organ—Soaps and ablution—Hot and
    cold bathing—Attention to the teeth—Importance of regular
    action of the bowels.

  The skin is an excretory organ, containing in its
substance innumerable  sweat glands, the ducts of
which open upon the surface.  Sweat or perspira-
tion is a slightly acid fluid, holding in solution
nearly  2  per  cent,  of solid substances,  chiefly
common salt, and various fatty acids and fats.
Besides  the  sweat  glands,  the skin  contains
sebaceous  glands,  which secrete  sebum, a fatty
substance, whose function is to keep the skin and
hair  smooth, moist,  and  supple.   The skin is
therefore  constantly  exuding  sweat and sebace-
ous  matter, which  mixed with shed  epidermic
scales or  scurf, accumulate on  the  surface, and
must be  periodically  removed if the surface of
the body is to be kept  in a clean and  wholesome
condition.
  A dirty skin,  like dirty clothes, is not only dis- 
    THE CARE OF THE SKIN, TEETH, AND BOWELS  235

agreeable  to  the  senses, but is  also  distinctly
injurious, foul and decaying matters on the  sur-
face of the body being liable to absorption  into
the vessels and  lymphatics  of  the skin, thereby
producing or  tending to foster various skin  dis-
orders.  It is  also the fact that  uncleanly people
are more liable to chill than those whose skins are
clean.  The salt in the dry sweat adhering to the
skin tends to absorb  moisture  from the air, and
the damp skin acting as a good conductor of heat,
leads to surface chilling and the production  of
cold.
   Inasmuch as the dirt to be removed from the
surface of the body is largely fatty in its constitu-
tion, the application of water merely is  insufficient
to remove it.   As everyone knows, hot water and
soap, and  plenty of friction  with the hands or a
flannel, are necessary to secure perfect cleanliness.
The reason of this universal custom is, however,
perhaps less well understood.
   Hot water is required to dissolve the fats in the
skin secretion, and soap is  necessary  to enable
them to be washed away.   Soap is essentially a
compound of  an  alkali  with a fatty acid.   The
alkali  of the  soap, when rubbed into  the skin,
combines with the greasy matters,  and enables
them to be easily washed off with water ; whilst the
use of the fatty  acid is to prevent the excessive 
236
THE ELEMENTS OF HEALTH
removal of the sebaceous  secretion, by which the
skin would be rendered over-dry, cracked, and
chapped.
  Coarse soaps containing an excess of alkali are
injurious to the skin, especially in cold weather,
the too great removal of sebaceous matter render-
ing the skin  liable to crack  and  " chap."    For
young children with delicate, sensitive skins, super-
fatted soaps,  containing no free  alkali whatever,
are often useful.
  In  very  cold  and  also in very hot  countries,
the native custom of  anointing the body with oils
or  greasy ointments  is  physiologically a  sound
one.   Exposure to the burning rays of the sun,
as well as to intense  cold, is liable to cause injury
to the skin, which  the application of oils has con-
siderable effect in preventing.
  After washing, the skin should be  rubbed quite
dry with a rough towel.   During this process the
loosened epidermic scales are removed, the  circu-
lation of  blood through the  superficial capillary
blood-vessels is increased, and the skin is materially
improved in texture and appearance.
  Whilst the  chief use of the hot bath is for pur-
poses  of  cleanliness, it  also has a sedative  effect
upon the nervous system, tending to allay restless-
ness and  excitability, and to  promote rest  and
sleep.  Hot baths  are best taken before  retiring 
    THE CARE OF THE SKIN, TEETH, AND BOWELS  237

to bed, as the body is readily chilled if  exposed
to  cold when  the  cutaneous blood-vessels  have
been relaxed by heat.
  Cold baths are less cleansing than hot, but more
stimulating and invigorating.  The best period of
the day for a cold bath is undoubtedly at rising in
the early  morning.  The immediate effect is the
withdrawal of heat from the body and the lowering
of its temperature;  but this is followed very shortly
by reaction—a feeling of warmth and glow—due to
dilatation of the cutaneous vessels, accompanied by
a sense of exhilaration and increased energy.  After
leaving the bath the skin should be rapidly rubbed
dry with a rough towel,  and warm  clothes quickly
assumed.
  A cold bath which is not followed by reaction is
likely to do more harm than good.    The absence
of reaction may be due to the water being too cold,
the bath being too prolonged, or  the  bather being
in a low condition of health.
  The temperature of  the water should be regu-
lated to the age and strength of the bather, and as
soon as reaction is established   the  bath should
cease.   Young and vigorous people can of course
endure  longer exposure to  cold  than those of
greater age in less robust conditions of health;
but it is a wise rule, especially in outdoor river or
sea bathing, to come out of the water as soon as 
238
THE ELEMENTS  OF HEALTH
the glow of reaction has commenced.  To remain
in the water until a sensation of cold is experienced
is to render bathing not only devoid of benefit, but
actually detrimental to health.  Outdoor bathing
should not be indulged in until at least two hours
have  elapsed since the last meal; and except for
the robust it is wisest not to  bathe on an empty
stomach, that is to say, before breakfast.
  The daily morning " cold tub"  renders the
bather little liable to take cold.   The  nerves of
the skin  are braced  to withstand  the shock of
cold from  draughts  or exposure, which to the
more sensitive skin induce chills and their conse-
quences.
  Cold baths are not well borne by young children,
and it is doubtful if it is wise to continue the daily
cold morning bath after middle age is reached.
  Even if the whole body is not washed daily, the
feet should never be neglected.  In the coldest
weather a very large quantity of perspiration is
poured out by the  sweat-glands on the soles of the
feet, and this requires to  be daily removed, along
with the dead scales which collect in the spaces
between the toes.  The feet become more offensive,
if not  frequently washed, than any other part of
the body.
  Cleanliness of the  hair  is also another matter
requiring strict attention, especially in children, in 
    THE CARE OF THE SKIN, TEETH, AND BOWELS 239

whom neglect of cleanliness very frequently leads
to the invasion of the head by parasites (lice).
   It is curious how frequently the cleansing of the
nasal  cavities is neglected, even by very cleanly
people.  A great deal of the soot and dust in the
atmosphere of large towns is prevented from reach-
ing the  lungs by becoming  lodged in  the  nasal
cavities  just within the  orifices  of the  nostrils.
The nose, therefore, performs to some extent the
very useful functions of a filter, but, like other kinds
of filters, it  requires to  be periodically cleaned.
This  can be best  done with a handkerchief and
tepid water, without soap, and it is wonderful how
refreshing this simple ablution is.
   The importance of keeping the teeth in a good
state  of preservation is now so widely recognised,
that it is perhaps unnecessary to remind the reader
on this subject, that bad teeth and toothless  gums
mean  deficient mastication of food, and in con-
sequence impaired digestion; and that it is hardly
possible  to attain  a healthy  old  age unless the
power of vigorous mastication is preserved.
   The care of the  teeth  is largely a question  of
cleanliness, although it must not be supposed that
cleanliness alone  will  render the dentist's aid
and advice unnecessary.   Under the existing con-
ditions of  civilisation, tending as they do   to
imperfections of  development and function, it may 
240
THE ELEMENTS OF HEALTH
 be said that every child would be the better for
 skilled supervision by a dentist from the time of
 commencement of the second dentition  (six years
 of age) until growth is completed.
   No doubt one of the causes of decay or caries of
 the  teeth is the retention of  fragments of  food
 between and  around the teeth.   These  matters
 quickly putrefy in the warmth and moisture of the
 mouth, and the products of decomposition attack
 the  enamel of the teeth, leading to decay of  the
 dentine beneath the enamel.   It is  impossible to
 keep the  teeth in a cleanly condition  if they are
 over-crowded in the  mouth or overlapping, hence
 the  importance of seeking the aid  of the dentist;
 but  in  normal mouths the daily use of the tooth-
 brush, applied to the inside of the teeth as well as
 to the outside and  grinding  edges, with  some
 prepared  tooth powder, is sufficient to maintain
 the teeth clean and wholesome.  To  remove frag-
 ments of food which  have lodged between adjacent
 teeth, there is much  to be said in favour of  a quill
 toothpick, but  any hard metal implement  should
 be avoided, as liable to injure  the enamel of  the
teeth.  Even better  than a toothpick  is the  use
 of antiseptic, waxed,  dental floss silk, which, when
drawn between  the  teeth, effectually  dislodges
retained particles of  food.
  It is hardly necessary to insist upon the import- 
    THE CARE OF THE SKIN, TEETH, AND BOWELS  241

ance  of  regular  action  of  the  bowels.    The
retention  of decomposable and decomposing sub-
stances in the  lower  intestine is prejudicial to
health; and there is no habit which tends so much
to comfort and  well-being as that which ensures
a regular  daily evacuation of the bowels.
  A large  and possibly increasing number of
people,  owing to  the  manners  and customs of
nineteenth century civilisation, are very much the
subjects of chronic constipation.   This is perhaps,
on the whole, a  matter on which  it is best to seek
medical  advice, depending  as  it  does upon  a
variety  of  considerations  of  physiological  and
medical import, which  have in some cases  been
alluded to in  the  chapters  on food and  exercise
(pp. 199,  201,  214), but which cannot very well
be further discussed with  advantage in this little
treatise.
16 
 
INDEX
              A
Air, see Table of Contents
Albuminates, see Proteids
Alcohol, effects of,  204
Alkaloids,  poisonous, in meat,
    186
Alum in bread, 199
Aniline dyes, 232
Animal charcoal filters, 28
Appetite, 178
Areas, open, for  houses, 147
Arrowroot, 201
Arsenic in wall papers, 157
Artificial illumination, 137
Ash-closets, 42

              B
Bacillus of tubercle, 85, 193
— of typhoid fever,  11
Back-to-back houses, 154
Bacteria in drinking water, 28,
    32 ; in the  soil, 142
Baking powders, 199
Barley, 200
Bath-heaters, 89
Bathing, hot and cold, 236, 237
Beans, 200
Beer,  205
Bell-traps, 68
Boilers, furring of, 3
Bones, nourishment in, 183
Bowels, attention to  the, 241
Brandy, 208
Bread, 197
Bricks, capacity for moisture,
    146
Burners, gas, 138
Butter, 196
               0
j Candles, 139
 Carbon block filters, 28
 Carbonic acid gas in outer air,
      78
 — in expired air, 81, 213
 — from combustion of coal-gas,
      87
 Carbonic oxide gas, 87, 90, 129
 Carpets, 155
 Caterham fever outbreak, 17
 Cellulose, 201
 Cesspools, 39
 Chalk soils, 161
 Cheese, 197
 Chicory, 209
 Childhood, clothing in,  231
 Chimney flues, 113
 Cisterns, 21
 Cleanliness of the person, 238
' Clothing, see Table of Contents
 Coal, combustion of, 122
 — gas, combustion of, 87
 — escapes of, 90
 — illumination, 138
 Cocoa, 210
 Coffee, 209
 Cold, catching, 223, 226
 Cooking, 172
 Cotton underclothing, 224
 Cows' milk, 189
 Cubic space, 99

               D
 Dairies, 195
 Damp-proof course, 147
 Daylight illumination,  135
 Defects, sanitary, in houses, 57 
244
INDEX
Gluten of flour, 166
Grates,  open,  124
— smokeless, 127
— ventilating, 129
Gravel soils, 159
Graveyards, 143, 161
Grease-trap, 70
Ground air, 141
Gully, yard, 67
Diets, 169
Digestibility of foods, 171
Disconnection of house-drain, 56
Domestic  dry refuse,  removal
    of, 36
Drains, 55
D-trap, 48
Dust, household, 154
— bins, 36
              E
Earth closets, 42
Eggs, 188
Electric light, 138
Enteric fever, 6, 11, 98
Evaporation of rainfall, 1
Excreta, 34, 199, 201
Exercise, see Table of  Contents
Exit-shafts for foul air, 112
Explosion of boilers, 4
— of  lamps, 139
Extractives,  182

               F
 Farinaceous foods, 200^
 Fatty acids in soap, 235
 Fats, 167
 Fermentation of food, 182
 Filters, domestic, 28
 — saud, 31
 Filtration of water, 28
 Fire-places, 121
 Fish, 186
 Floor space,  100
 Floors, 149,  152, 156
 Flour,  197
 Flush-tanks, 71
 Fogs, 92, 123
 Food, see Table of Contents
 Foundations of houses, 144
 Fruits, 202
 Fungus from damp, 146
 Furniture, house, 155

               G
 Galton's grate, 129
 Gas, see coal-gas
 Gelatine, 183
              H
Hardness of water, 2
Hinckes-Bird's window  venti-
  lator, 110
Hopper water-closets, 45
Hot-water pipes, 134
House-drainage, 55

              I
Illumination of rooms, 135
Inlet openings into rooms, 107
              L
Lamps, 139
Lead, solvent action  of water
    on, 5, 25, 211
— pipes, 26, 52, 63
— poisoning, 5, 158, 211
Lemon and lime juice, 203
Lighting, see Table of Content
Lime salts in water, 2, 16
Linen, 224
              M
" Made " soils, 144
Manhole chambers on drains, 56
Margarine, 196
Marshy soils, 160
Meal times, 176
Meat, 180, 183
Middens, 39
Milk, 188
Mineral  salts in food, 167
— waters, 210
Muscles, exercise of, 213, 215
Mustard, 204
              J
Joints of drains, 55 
INDEX
245
              N
Nitrates from oxidation of sew-
    age, 11
Nitrifying organisms, 15, 35
Nitrogen in air, 82
— in food, 166

              0
Oatmeal, 200
Offensive trades, 97
Old age, clothing in, 231
Organic matters—
     in air, 80, 98
     iu soil, 142
     in clothing, 232
Outlets for vitiated air, 113
Ovens, kitchen, 185
Overflow pipes from cisterns, 22
Overcoats, 225
Oxygen in the air, 77
Oysters, 187
Ozone,  79
Pail closets, 41
Pan and container closet, 47
Pasteur-Chamberland filter, 29
Peas,  200
Pepper, 204
Percolation of rain, 2
Perspiration,  necessity  for re-
    moval of, from skin, 235
Phthisis, produced by—
    foul air, 85
    damp soils, 140
Pollution of rivers, 5
— of  wells, 9
Portland cement, 55
Potatoes, 202
Proteids, 166

               B
Radiation, warming by,  131
Rain water,  2
— pipes, 65
Reaction after bathing, 237
Reservoirs, water, 19
Respiration, 81
Rest after exercise, 214
Rice, 201
Rivers, pollution of, 5
Sewer air, 93
Silk, 224
Siphonage, 53
Siphon flush tank, 71
 — traps, 44
Sites of houses, 159
Skin, care of the, see  Table of
    Contents
Smoke, prevention of, 93, 127
Soap, 235
Softness of water, 2
Soil-pipes, 51
Soils, varieties of, 160
Springs, water, 17
Staircases, 152
Starches, 167
Stoves, heating, 131
Subsoil, 140
Sulphurous acid gas, 91
Sunlight, 79, 135
Surface water, 67

              T.
Tannin of tea,  209
 — of wines, 207
Tea, 208
Teeth, preservation of, 239
Testing of drains and  soil-
     pipes, 58
Tobin's tube, 111
Training, 220
Traps, water, 44
Tuberculosis, 85, 193

              U.
Underground water, 8, 146
Urinals, 65
Underclothing, 223
                  17 
246
INDEX
              V.
Valve closet, 49
Vegetable acids, 167
 — diets, 170, 201
Ventilation, see Table of
    Contents
Vinegar, 203

              W.
Wall-papers, 157
Walls of houses, 147, 151
Wash-down closet, 45
Wash-out closet, 50
Waste-pipes, 60
Waste waters, 34
Water, see Table of Contents
Water as food, 168
Water-bearing strata, 8
Water-carriage system, 35
Water-closets, 44
Water mains and pipes, 25
Waterproofs, 225
Water-softening process, 27
Water-waste preventers, 51
Wells, 7
Wheat flour, 197
Whisky, 208
Windows, 136
Winds as ventilating agents,
     104
 —  effects of, on body, 225
Wines, 205
Wool, 223

              Y.
Yeast, 197
Yard paving, 150
             PEINTED BY ADLABD AND  SON,
BABTHOLOMEW CLOSE, B.C.,  AND  20, HANOVER SQUAEE, W. 
 
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