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\\ PHYSIOLOGY, PATHOLOGY,
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THERAPEUTICS
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MUSCULAR  EXERCISE:
A  PAPER
READ BEFORE
THE COOK COI NTY MEDICAL SOCIETY,
PUBLISHED AT THEIR REQUEST.
   W. H. BYFORD, M. D.,
Professor of Obstetrics and Diseases of Women and Children in Rush Medical College.
       CHICAGO:

JAMES BARNET, BOOK, JOB AND CARD PRINTER,
   CORKER LAKE AND WELLS STREETS.
        1858. 
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NATIONAL LIBRARY OF MEDICINE




       Bethesda, Maryland
 
     PHYSIOLOGY, PATHOLOGY AND THERAPEUTICS

                           OF


MUSCULAR    EXERCISE.


     [Read before Cook Co. Medical Society, and published at their request.)


                     ---i-
             BY W. H.  BYFORD, M. D.


                       PHYSIOLOGY.

  Phenomena.—When an individual exercises actively to the
extent of producing perceptible effects, there are a glow of red-
ness on the surface, an increase of  temperature, perspiration
and  respiration.   These circumstances are apparent to the ob-
servation of the most careless observer.   Upon closer scrutiny
into  the manifestations of muscular exercise, we find the heart
and  arteries beating rapidly and several  of the secretions in-
creased in quantity, and their peculiar products enhanced to a
considerable extent.   The urinary secretion, the secretion of
the liver, skin and the pulmonary excretion, are all carried on
more actively than in a state of repose, while the secretion and
excretion of the alimentary mucous membrane are diminished.
I speak now of an amount of exercise  that produces quite
obvious phenomena.  I am inclined  to the opinion, however,
             1 
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•J
that moderate  and prolonged exercise increases  all the excre-
tions  beyond what they are in protracted  repose.   These are
the more obvious  phenomena  of  exercise.   The  interesting
question now arises,  how are  they produced ?   What are the
intimate circumstances  transpiring during the exhibitions men-
tioned ?  Voluntary motion of the  muscular organs is preceded
by innervation, the production  and transmission  of the power
of the will, and the contraction of the muscular fibrilla.   Every
functional action of whatever kind occur as the  effect of cell
change.  This proposition is  true  in relation to the production
of the power of volition in the brain and the contractions of the
muscular fibrilla,  as well as the  secretory  processes.   Each
time the nervous or mental action is effected, cells receive from
the cerebral tissue  and impart to it certain elaborate and effete
material; the  latter derived  from  the  disintegration of the
nervous  or  cerebral mass,  and the former  to  be used for its
repair.   So also the muscular tissue at each contraction re-
ceives through the medium of  cell action  or change, material
from  the blood intended for the repair of the damage sustained
during contraction, and throws into the circulating fluid through
the same agency the effete substance lost in its disintegration.
We may state  it  as a correct proposition, that  one of the
necessary conditions of action in an organ is organic  destruc-
tion or  disintegration and repair.   The disintegration occurring
simultaneous to and most  likely being the  result of action  in
each  particular  instance,  and  the repair  a  necessary  pre-
requisite  to future  action,  the  organ in this way  would
constantly  retain its  integrity  of structure, notwithstanding
ever-recurring  change, as the effect of  action.   Chemical  or
vital  affinities,  or  both,  between the  changing tissues and
the constituents  of the blood, effects this interchange of sub-
stances  as  rapidly  as  the  acting  organs  are called  upon  to
perform their functions.   This principle, it will be seen, pre-
cludes  the probability of organic change being left behind  as
the  result  of action while  the  organ remains capable of its
duties,  and teaches the  doctrine that so soon as the  play  of
affinities from  any cause is  so weakened, or rendered impracti-
cable from want  of nervous stimulus or blood products, that 
3
repair is not perfect, the  function  will  be imperfectly dis-
charged, or entirely cease.   Any disease of the nervous system
that  disturbs its presiding  capacities,  as  in  fevers,  severe
shocks,  pressure  upon  the  brain, etc., thus  incapacitates a
certain portion or the whole of the system, owing to the extent
and gravity of the nervous lesion for functional action.   The
reciprocal  affinities in this case are lost for want of nervous
agency.   If the nervous system be but slightly affected, the
affinities are merely  more tardy; if gravely, they are entirely
suspended.   Thus, the blood  and muscle may both possess all
of their  own special  chemical and vital properties, and yet not
be capable  of acting  and reacting upon each  other, then the
muscular contraction must cease.
   You will recognize in this statement of conditions the patho-
logy of paralysis  from cerebral congestion,  pressure  from ef-
fusion, or pressure or inflammation on or  in a large nervous
trunk.   Another source of functional  tardiness and  even sup-
pression, is the want of the proper  material  to  sustain the
organs in a state  of  integrity under functional action.   If the
blood is  prevented from elaborating the various  materials which
go to form nerve and muscle, from the presence of some poison
as carbon, urea, bile, etc., the functions are  performed imper-
fectly, and  if carried to  a  great degree of contamination, the
blood is  entirely incapable of supporting functional action, and
these all cease.   If also from want of nutrition, the blood does
not receive the substances  from which muscle, nerve or other
organic elements may be produced, these last will not be elabo-
rated,  and  hence  the chemical  affinities resulting from  their
presence could  not  take place, the muscle  cannot  act with
energy, if at all, the  nervous functions are performed irregu-
larly and imperfectly, the secretions are scanty and unhealthy,
because  the  material  out of  which the repair after functional
changes in the organ  is not supplied, and all  succeeding efforts
become more and  more  imperfect until they  cease  entirely.
This is the condition  of things  in anemia, and it accounts for
the tardiness of the bowels, the  imperfect secretion of the liver
and other intestinal  organs,  the whole phenomena in fact of
that state  of the circulating  mass.  This play of  affinities be- 
4
tween  the  circulating blood in the capillary bloodvessels  and
the changing tissue, the fibrilla of the muscles and the nervous
structures, engaged  in muscular exercise, is the starting point,
I think, and  a sufficient  basis  upon which we  can found  a
rational  and I  hope not  unprofitable explanation of all  the
phenomena observed.
  In  the composition of the blood  are contained all  of  the
separate ingredients of all the tissues in the body either elabo-
rated,  so as to immediately enter into the composition of these
tissues while passing them  in  the  capillary tubes, or to be
readily and easily changed by the  chemical or vital affinities,
or both, of the organs to which they are appropriated.  These
ingredients  must possess  distinctive  differences  to  a certain
extent at least, so that we  may say with great  propriety, that
in the blood are contained muscular fibre, nerve  fibre, bile,
urine,  bone, and so on to all the products  of functional action
and nutrition, either ready formed, only awaiting separation,
or formed,  requiring elaborating mutation  by means of cell
action, to  be appropriated  as  needed,  for the formation or
repair  of structures.  Another proposition  forces itself upon
our mind in this connection as necessarily true, viz: that these
ingredients must exist to a limited extent of quantity only and
something of definite proportions to the probable  wants of  the
various organs used, owing to the habits to some extent of  the
individual.  The man, for instance, whose muscle  is called into
action  to a  greater  extent  than  any other system  of organs,
will require more food from which muscle tissue may be formed,
and his chyliferous and sanguiferous peculiarities will be that of
muscular elaboration, those  organs  will become large and be
kept in a state  of perfect nutrition, at the  expense perhaps of
the brain.   Individuals, on the other hand, whose  functions  are
mental exclusively, will have an abundance of  neurine  in  the
blood ready for use, while the muscle cannot be nourished to such
an extent as to admit  of more  than very moderate muscular
exercise.  We often have examples of partial impoverishment of
the blood of this kind brought  about by habits.  If the man of
muscle was called upon to exercise his mind long and intensely
he would soon  have the  headache, lassitude and exhaustion in 
5
fact as readily become exhausted with this kind of unaccustomed
effort as the brain worker would if required to labor actively at
anything  that  required  muscular exertion.   These habits and
capacities may be at least partially changed by gradually bring-
ing about  different habits in the two individuals, and with it
different sorts  of nutrition and the  necessity of different diet.
It must be remembered that all these ingredients, intended for
different purposes, are thoroughly mixed  together and circulate
in company  to all parts of the  system,  so  that  through  the
capillary vessels of the brain we have the neurine with the mus-
cular, bilious and other materials, instead of  the neurine alone.
The affinity of the nerve fibre for its peculiar material of support,
through the  agency  of cell  metamorphoses,  takes up from  the
blood its own nutritive elements and leaves the other ingredients
to pass along and be elsewhere appropriated for other purposes.
Of course it is supposable that  only just so much material is
abstracted as is needed for repair and growth and no more, and
if the blood  is still rich in such ingredients, much of them pass
on to be returned in  the general course of the circulation.   In
like manner  the material for the formation of muscle is arrested
and appropriated as needed, as with every other peculiar material.
The more  actively the function  of any organ is proceeding,  the
more rapid is the play of affinities between its intimate structure
and the blood  in  the capillaries.   The blood, by means of  the
attraction of the acting organ in its atomic changes, is attracted
into the capillaries in increased quantities, the attraction being
always from  the arterial extremities  of these minute tubes.   It
is thus drawn from the arteries by this attractive force.  So soon
as the chemical or vital changes have resulted in  the repair of
the acting structure, this artero-tissual  attraction ceases,  but
now there  is  thrown into the stream of passing blood the effete
material resulting from tissual disintegration, where  there is
another force developed, a kind of tissue-venous repulsion which
urges it forward in the veins.   These are the main elements of
force  in the capillary circulation, the attraction of interstitial
and separative nutrition and the  repulsion of interstitial disin-
tegration and  distinction.   Now to justly estimate the effect of
these forces, it will only be necessary to recollect that the tubal 
6
area of the capillary vessels, compared  to that of the arteries
whence they are supplied with blood,  is  four hundred  times
larger.   Hence, if nutritional attraction is feeble—which it cer-
tainly is—when exercised by a single cell, it becomes enormous
when billions of them combine in pulling  in the same direction.
In fact, I have sometimes fancied that  if all the organs could
act simultaneously through  all their capillary vessels, so much
blood would be  thrown through the veins upon the heart  as to
burst it  from  excessive  accumulation.  If, on the other hand,
all nutritive attraction were to cease, the blood would accumulate
in capillaries, cease to evolve caloric and the circulation to  stop.
Indeed, it is quite probable  that such is the condition of things
in extensive congestive collections in different parts of the body,
or of a general character.  In cholera, in which there is general
congestion, this seems to some extent to  be the case.  The blood
stops in the  capillaries  and passes through them with  great
difficulty, either on account of its altered condition or the arrest
of nutritional changes going on necessary to keep up the circu-
lation, the watery portions transude through the skin and mucous
membrane, while  there is  a  complete want of  response to
medicinal appliances, as though  the  functions of the stomach,
both absorbent and digestive, had entirely ceased.  In repose,
or an  accustomed degree and kind of exercise,  the  capillary
flow of blood is such as to keep up a pulse, say to 75 or 80 beats
the minute.   In walking or standing, in persons accustomed so
to do, there is very little acceleration of pulse, but when a larger
number  of  muscles  than  usual  are put  into  operation, the
increased area of capillaries  are being acted  upon by this
nutrition affinity, and consequently a larger amount of blood is
poured into the veins and thence into the heart, which is stimu-
lated to greater exertion and also the whole circulation.   The
relative affinities  between the blood  and  the tissues may be
increased therefore by an increase of function in the latter; the
more active  a  muscle  is contracting  and relaxing,  the  more
rapidly its changes of disintegration and repair is going forward,
the  greater amount of nutritive material it  is attracting  from
the  blood.    In persons whose blood is  rich  in albuminous
material for the support of muscle, the less will be the arterial 
7
excitement—other things  being equal—because  the muscles
derive their pabulum from a less quantity.  If,  however, the
blood is impoverished in the material necessary for the support
of muscle, it is drawn through the capillary vessels more oopious-
ly, in order they may receive  the  same supply.   This explains
the exciting effect of exercise in anemia.  The capillaries must
pass a large amount of impoverished blood through the muscles,
or a large amount of it is passed through quite rapidly in order
that they may  derive material for  their repair.   This  being
poured into the  veins, it goes  more rapidly than ordinarily into
the heart, which is very excitable, and it is thrown  into tumultu-
ous  action.   There are many good  reasons  deducible  from
experiments and observation  for believing  this  to be the true
explanation of  the  physiology of  exercise.  The mechanical
effect of the muscles in pressing the blood  forward toward the
heart—for on  account of the valvular fixtures in  the veins pass-
ing through the muscles, they  cannot press it  backward—by
squeezing the vein between them, has been supposed to, in some
measure, account for the acceleration of the circulation of the
blood, and the sweating, heat, etc., to be the effect of the latter
phenomenon.  But, as I shall show from experiment, this cannot
be an explanation in all cases.  The  secretions and excretions
seem to be stimulated to an increase  by the mere presence of
the ingredients forming their  products in a more than ordinary
quantity.  The  kidneys may  be stimulated  to increased action
by a more than ordinary quantity of water in the blood, and
by medicinal agents in the circulation.  The proper office of
the excretory organs, however, is to  carry off the waste sus-
tained by functional action in the active organs.   They attract
the materials of  secretion  in their capillaries from the arterial
extremities of these  tubes, and thus may add or produce arterial
excitement just as functional action in other organs may do the
same.  The mere transudation of water  through the  skin and
mucous membranes  of the alimentary canal or kidneys as not
forming  a part  of the  cell action in secretion, must be con-
sidered an exception to this rule.  A prominent example of this
kind  of  excitement  is the  secretion of  sugar by the kidneys.
Diabetes is always attended  by increased arterial  excitement, 
8
and yet post mortem  examinations  have not revealed any pe-
culiar inflammatory lesion  to  account for reaction.   In  fact, I
think we may regard  it as a rule, that increase of function
above the natural standard of activity involves  an accelerated
circulation, greater or less according to the circumstances of the
case. Exceptions to this rule  possibly may be summoned by the
memory of some of  my friends here to-night, but they  do not
just now occur to me;  and further, the longer functional action
continues, the  greater will be the velocity of the circulation.
This constant increase of circulatory velocity is dependent upon
one  of  the circumstances  mentioned above,  viz:  the definite
amount  of ingredients  intended for the support  of functional
activity  in each organ; something  like a  definite amount of
material for  the repair of muscular structure during its acting
condition.  This substance in  a  state of preparation is diffused
throughout the whole  circulating  mass.   After the process of
repair has been kept up during  muscular action for some time,
the  quantity will  become lessened, so that  the  blood to some
extent is impoverished of this  particular class  of ingredients,
and a greater amount of blood must  be  circulated through the
muscular fibres in  order to impart  to them an adequate amount
of support,—just as  a larger amount of unnutritious aliment is
necessary to  impart the nourishment that  a smaller quantity
would afford  if more  concentrated.  This decrease of material
and increase of excitement bear  a  direct proportion to each
other, until the blood becomes so  much exhausted as to be in-
capable  of supporting  the  organs  under further exertion, when
the  exercise  must cease;  not from  damaged condition of the
acting organ, but  from the exhausted  condition  of the blood-
The most interesting proof of this theory of the physiology of
muscular exercise  is  derived from the effects of muscular con-
traction without motion of the  limbs, such general contraction
of antagonising muscles as to  prevent motion.  It will be found
by  experiment that when  an  individual is sitting at apparent
ease, if he places  all the muscles of one lower extremity in a
state of great  contraction, from the hips to the toes, that his
pulse will be accelerated from  twenty to  twenty-five beats in
the minute, and of both lower extremities some ten more.   By 
9
simply holding  one arm horizontally,  it will  accelerate  the
pulse from four to ten beats.
   I have tried a great variety of experiments of this kind, and
I find the  larger number of muscles, and the more violent the
contractions, the  greater the arterial excitement.   I have very
little  doubt but that one half of the soft parts of the whole
system in weight is  made up  of the muscles  and their appen-
dages.  If this be a true supposition, the area of their capillary
vessels is  two hundred times larger than  the whole of  the
arteries in  the body, and it is  not to be wondered  at that  a
small increase in the  rapidity  of the current  in an  area  of
nearly a hundred fold  more tabal space—as one leg and hip—
should cause perceptibly  increased  action  of the  arteries.
Another fact of no small importance to the physician deducible
from  the  experiments I have performed and witnessed of this
kind  is,  that this static  muscular contraction  produced  more
effect upon the action of the heart and arteries than locomotion.
I think this results from the circumstances that the muscles of
the legs in locomotion are not all in a state of contraction at the
same time, but alternately contract and relax, one set carrying
the limb forward while  the  other set is relaxed.  There is yet
another remark I desire to  make about the physiological action
of muscles.  Although the  body of a muscle may be continued
tense for a considerable time, the whole of the  fibrilla  are  not
in a state of unvarying  rigidity, but the organ, when closely
observed, will be  seen to tremble and twitch in small  portions,
each portion being in a different part every instant of time, and
upon  auscultation the contraction and relaxation of the fibrilla
composing its bulk may be heard very plainly.  There can there-
fore be no  doubt that a part of the fibrilla are contracting while
the others are relaxing and repairing, ready for another con-
tractile  effort.   For an instant,  in  a jerk or sudden start no
doubt, all the fibrilla may act in unison, and those are the over-
whelming contractions  that snap asunder the tendo-achilles, or
the muscles themselves,  or back bones, etc.; but such contraction
cannot be maintained even for a moment.  Only a part will act
at a  time on a  strain, and the  longer the  stretch the more
ineffectual and feeble this general contraction becomes.
• 
10
         PATHOLOGICAL EFFECTS OF MUSCULAR EXERCISE.
  As with  every other condition  and circumstance which may
produce disease, the  effects of muscular exercise will vary, and
its  ultimate  morbific action  will depend  upon many  things.
Constitutional proportions of the different  organs  of which the
body is composed will modify the effects of exercise, as also the
different conditions of them.   The tumultuous effects of violent
exercise  upon persons laboring under pulmonary and  cardiac
affections would be  easily predicted.  Dyspeptics, from  their
incapacity  to digest, assimilate and repair the waste resulting
from the wear of protracted muscular action, would soon succumb
to their exhausting exactions upon nutrition. Persons too whose
kidneys, skin, or other emunctories are so damaged as to perform
excretion imperfectly, soon  poison  their own  blood  to  such a
degree, under voluntary exertions, that they are soon arrested.
Climate has much to do in enabling man to undergo great fatigue
without damage.  The tropics are peculiarly averse to great
and protracted physical  labor, probably on account of  the  air
being so rarified as not to oxygenate the  blood sufficiently in
quantities respirable by an ordinary pair of lungs.   Extremely
cold climates, although affording oxygen in compact manner, is
probably so sedative  in its influence as not to be most favorable
to enterprise.  Experience proves to us what sound physiological
knowledge  would suggest, that the  temperate is much the most
favorable zone for  man and the enterprises of civilization.  All
the circumstances  necessary to enable  man to  do more  work
without damage  to his physical system are here combined in that
happy manner, as not only thus to capacitate him, but to stimu-
late him to ambitious and profitable industry.   Diet is another
one of the most certain modifying circumstances in this respect.
Impoverishment, debility, and  organic evil is  sure  to  work
destruction upon the unfortunate laborer who lives on insufficient
fare.   Nor can we leave out  of  the question  habit.   Laziness
incapacitates man for labor, and it would  be  almost certain to
make a lazy man sick to commence  hard labor upon any sudden
emergency;  and we seldom  see  people physically capable of
field or mechanical labor who have led a  life of  indolence up 
11
to mature manhood, and if by mental discipline they force their
muscular  system  into  laborious employment, the  effects  are
disastrous in the great majority of instances.
   In order, however, to arrive at the proper morbific influence
of exercise, we  must observe its effects under all the  circum-
stances in which man is placed, while also we bear in mind the
degree and kind of exertion.
   It will probably be best to commence with a consideration of
the acute effects, if I may use the expression, of violent efforts,
and  afterwards  take a view of the more gradual  inroads upon
health made by  protracted toil.   Violent muscular contractions
often cause tendinous  ruptures, as  in  the  case of  the tendo-
achilles, an instance of which my friend, Dr. C. G. Smith, men-
tioned to me recently as the result of violent muscular efforts in
dancing, as also hernia, etc.   Rupture  of their own substance:
a very interesting case of this accident  occurred in the  practice
of a friend of mine  several years ago;  the rectus  abdominis
tore across about  the junction of the upper two-thirds with the
lower third.   Bloodvessels have also been  ruptured, and fatal
effusion in the brain, chest, or abdomen, the consequence.   The
heart itself, a powerful  muscle, may be lacerated by the  distend-
ing influx of blood, an instance of which I once knew in the case
of an athletic man standing under a heavy load.   The patient
staggered, fell with his load and never rose.  Upon examination,
his heart  was lacerated  and  his pericardium  distended with
extra cardaic blood.   Thousands of such disasters are constantly
occurring  as the  accidents of muscular exertion,  but it is with
the less direct influences  that we are now most concerned.   It
may not be irrelevant,  perhaps, to consider for a moment what
fatigue is, what  its character, and what its import.  I mean by
fatigue  that  muscular inconvenience,  dependent  upon over
exertion (local) in  the muscles of the legs  when  it  has arisen
from walking, in the arms when they have been  the members
used, etc.   This  local fatigue is, doubtless, the result of increased
vascular action in  the parts the capillary vessels have been  and
continue to be  more than ordinarily distended with blood, in
order to keep the parts properly supplied with nutritive material,
and  is caused by  the nutritive  affinities in  the tissues.   When 
12
this increased vascular action is continued for any length of time,
it may become local inflammation and not pass off by rest mere-
ly, particularly when  other circumstances favor such a state of
things.   The lungs may also become the focus of local irritation
and  inflammation as  the effect of  excitement  from  exercise.
The  brain, in  fact most of the important viscera, may be thus
affected,  but I think by far the most morbid effects of exercise
are indirectly produced  from it.  The suppression of excretions,
rendered more active by exercise,  is a source of aggravated
difficulty, if not a primary result of the excitement of exercise.
In order to elucidate the idea I wish to convey, I will mention
a few facts that are known to exist.  During active exercise the
blood is loaded with excrementitious substances, as carbon, urea,
or its proximate  principles, etc, and these  are  finding outlets
through  the exhalations from the  lungs, skin  and  increased
urinary discharge.   The dupurating process  is commensurate
with the  necessities for it, and the blood is  maintained in  such
a condition as is necessary for the  support  of the  vital and
nutritive processes of  the  system to a healthy degree,  each
emunctory having its own peculiar effete substance to eliminate,
and when not interrupted, all goes on well; but should one or
more of these emunctories fail to perform their  duties, some of
the excrementitious substances fail to find their  way out of the
bloodvessels, and being retained  in the mass  of blood,  to a
certain extent poison  that fluid, and render it  incapable of per-
forming  all its complicated offices.   This is  the reason  why
suppression of cutaneous excretion proves so disastrous, when
the individual is  laboring  under the wearing  effects of violent
exercise.   We know from  experience that it  is not simply the
stoppage of perspiration, for  if perspiration  induced by  heat
be stopped, the effects are not nearly so disastrous as if pro-
duced by violent  exercise.   The recrementitious contents of the
blood are smaller in quantity and perhaps less  poisonous in char-
acter. It should be remembered, however, that there is no time,
even  in  the most calm condition of the functions, but  what
excrementitious substances do exist in the  blood, to an extent
of quantity sufficient to prove  deleterious  to the  organism if
detained by suppressed excretion.   I think it is thus our most 
13
violent inflammatory diseases are  produced.   I desire to be
understood as not denying the repulsive effect of suppression of
excretion.   This is often effective, I have no doubt, in the pro-
duction of local determination, but I do wish to make a distinc-
tion between this effect and the retention of morbid excretion.
I wish  also  to  say that much stress  is due  to  the time — in
relation to  exercise—when this  suppression  occurs, as to the
gravity and direction of the effect produced.
  Its chronic effects upon the muscles are well known.  It almost
invariably results  in hypertrophy.   The  muscles concerned
become larger and capable of more than usual power.   And no
doubt but that nutritional increase may be carried to a great
extent if everything else favors.   The most interesting, however,
is the chronic effects upon the blood, and through it upon the
organization at large, or some particular organ or group.   This
subject has not commanded the attention which ought really to
attach to  it, and hence there is not much known as to what the
effects of excessive muscular exercise, continued for a long time,
would be.  The instances which usually fall under our obser-
vation are such as are combined with privation  and often other
deleterious influences, so that we  cannot separate the evil of the
various causes.  Excesses in this  way, however, must lead to
changes in the composition of the blood, abstracting, on the one
hand, the material for their support,  and thus, in one sense,
impoverishing it;  and on the other,  pouring into the blood excre-
mentitious substances evolved  by  muscular detritus, and thus
injuring its composition.   There  can be no doubt that  exercise
for days,  without the proper intervals of rest in this way, very
much impairs the quality of the  circulating mass, and produces
morbid determinations, often  to the  brain,  lungs, abdominal
viscera, etc.  I think there are many reasons for believing that
the blood cannot elaborate the  materials of digestion  poured
into it through the stream of chyle, derived  through the chylo-
poietic organs, without some intervals of  rest; that the several
hours rest of night afford the  blood time to recover from the
exhausting influence of the  exercises  of  the day;  that sleep is
a blood repairing process instead of an organ repairing interval
from labor.   The  first effects  then of protracted  labor  would 
14
be impoverishment of the blood of certain substances intended
for the support of the laboring organs, an increase of the velocity
of the circulation, in order to compensate in quantity of blood
for the want of richness, until it amounts to morbid excitement,
and  with local  determinations to the organ  operating.   This
may proceed so far  as  to induce  inflammations of the muscles
of the brain, etc.  The great exertion necessary on the part of
the central organ  of circulation will  induce hypertrophy, with
all  its evil  effects upon the lungs, etc.   In a more moderate
degree,  exercise, to too great an extent compatible with health,
would cause simply  functional derangements,  from the changes
of the blood I have just mentioned.  The abstraction of certain
elements from this  fluid must prevent its  chemical and  vital
reactions from taking place normally, in such  a way as to  keep
up any of the functions correctly.  I cannot forbear, although
it may be not strictly in place, to consider, in  this relation, the
effects of want of  exercise in a short way.   The immediate or
early effects  of inactivity, as observed by the medical man, is
in most instances plethora and often local fulness, particularly
of the head,  scanty secretions and excretions, costiveness, loss
of appetite, etc.   This condition of things is often followed by
depraved secretions,  the tongue is coated, various nervous symp-
toms  show themselves in general malaise.  There is always felt
a strong desire to  move  about, the muscles must be  stretched,
with yawning and  gaping.   Now the  symptoms of disease that
occur as the effect of want of exercise, is very different from
those, the result of excesses, in this respect.  Excrementitious
materials are not retained in the blood, hematoxy does not take
place, but there is  too great a production of nutritive materials
for the organic expenditure, and if digestion remain  good and
hematization is  efficient, more albumen  is elaborated than the
muscles and nervous system consumes, a larger amount of cor-
puscles, white and red, exist, than is necessary for  oxydation
and  repair.   There is too  rich a condition of blood for the
meagre demands.  The acute effects of this real  plethora  is to
embarrass most of the functions, produce hemorrhages, apoplexy
epistaxis, hemorrhoids, etc.   The sudden transition of persons
in good health, from  an active mode of  living  to that of seden- 
15
tary habits, very often lead to diseases of a plethoric character,
highly dangerous  and often  fatal.  I  will digress  here  long
enough to say  that  we should  always  discriminate  in  local
disease, between those arising from suppressed secretion, and
consequently in systems possessed of poisoned blood, and those
coming up in case where plethora  exists, from acute plethora
developed in .recently assumed habits  of inactivity.   I think
the illustrious General Taylor is an example of the fatal influence
of  such a  change of  habits.   Doubtless,  such instances  of
disease would bear depletion far better than those originating
in other causes.
   But  supposing that these acute effects  are not developed,
and the habit of inactivity and its consequences continue, what
are we to expect ?  Now, I consider this one of the most inter-
esting  points of pathology,  and I regret that the state of our
knowledge and my own deficiency of information on this point,
prevent me from doing justice to it.
   I shall, however, say, in a.very brief manner, such things as
my experience and reflections enable me.  If the opinion I have
 expressed above be true, that the blood is the great laboratory
in which the nutritive materials  are prepared ready for their
 immediate uses, and  that each one of these ingredients are pre-
 pared  in  a  definite  quantity and of  separate quality,  as for
 instance  such as are  intended to  repair the muscles, such as go
 to supply the  wear upon the nervous system, etc., and that in
 order  to be readily excreted they must be used for such pur-
 poses and cast off as refuse matter, it must follow that  these
 materials will  vary  with the draw upon them by the  acting
 organs.
    I do not assume  that ingesta  may not be excreted without
 first passing through these  respective  structures, but that it is
 at least unnatural and unusual, and doubtless often  gives rise
 to  embarrassment in the  secretory  and excretory  apparatus
 through  which they pass.   I believe,  too,  that many of these
 different ingredients, after  being  thoroughly prepared for use,
 are retained, and raise the albuminous compounds to a higher re-
 lative proportion than normal.  This, at first sight, would appear
 of little  consequence, but upon closer examination I am induced 
16
 to believe that a class of the most obstinate and fatal affections
 arise from, or at least their cause are made more effective by
 sedentary habits, and habits of inactivity.  I allude to scrofulous
 and tuberculous disease, which  I think ftught  to  be classed
 together.  My  accomplished  friend, Dr. J. N. Graham, at my
 instance, commenced a series of experiments upon dogs, to see
 how absolute  confinement in a close box would effect them, so
 that they could not turn around  or in any way exercise their
 limbs, and yet have a good supply of pure air and good food.
 Although these experiments were not so numerous and varied
 as to justify positive conclusions, they unquestionably produced
 the very best  specimens of tubercous infiltration in the lungs,
 as also some of the other organs.  These lungs may be seen at
 his office in Portland Block, by any member of the society who
 choose to call  and examine them.   The effect was so complete,
 and resulted  apparently so entirely from confinement, that he
 is equally with me of the opinion  that they stand in the rela-
 tion of cause  and effect.   This opinion is strengthened by the
 fact, that the wild animals  caged  in  the  different menageries
 and zoological gardens die  almost invariably from tuberculosis.
 Observation on the  human  patients, I think, still fortifies the
 conclusion.  The robust hunter and frontiersman or his family
 scarcely  ever have scrofula  or consumption.  I  have not time
 and space in this connection to adduce any further evidence of
 this kind; but I believe reflection  on what you have seen, and
 observation in  future, will furnish you with numberless examples
 of this kind.  And this is quite in accordance with physiological
 laws.   Before reminding you of these, however, I will  mention
 a fact with which you all are no doubt familiar:  that tubercu-
lous and scrofulous deposits belong to the proteinous compounds,
and are identical in  chemical  composition with these as found
in the blood  in the shape  of  albumen, fibrin, etc.  Now, the
physiological laws to which I have alluded are, 1st, that when
an ingredient becomes redundant in the blood, it has a tendency
to effusion  in  the tissues, or completely out of the body; and,
2d,  that when  an effusion in the tissues takes place, the fluid
portions are absorbed, and  the  solid, becoming compact, act as
irritants, and  are discharged  by suppuration—instance apo- 
17
 plexy,  etc.  Now, I  think, this is  just what takes place m
 tuberculosis;  the albumen, which is  elaborated in and through
 the blood,  becomes superabundant,  because not  used ^by the
 muscles and  nervous  system  in  a  state of inactivity,  and is
 effused in the tissues in the shape of  tubercles in the lungs and
 cheesy deposit elsewhere.
   Two facts somewhat relevant to this theory is, that in tuber-
 culous persons the proportion of albumen is highly preponderant,
 and that the  chemical composition  of muscular fibre is that of
 albumen.   Other causes augment the tuberculous diathesis and
 determine  the location, shape  and time of deposit.  Irritation
 from cold  would  cause  an unusual  collection of blood in the
 lungs, and encourage  the  deposit in  them; intestinal irritation
 would produce  the  same  effect in concentrating  the fluid  and
 deposit in  the abdomen; premature or morbid excitation in the
 cranial cavity would induce tuberculous meningitis.   May I not
 also claim  the broken-down tuberculous condition, developed by
 long confinement, from serious accidents, as fractures, crushed
 limbs, etc., as confirmatory evidence  of the theory?  But I am
 prevented by time from discussing this interesting  branch of the
 subject farther.  However, I hope, as cultivators of our beloved
 science, you will examine  it with sufficient patience to confirm
 or falsify the  conclusions to which I  have  been forced  by the
 weight of facts, as I have  seen them.
   This disturbance of  quantitative and qualitative composition
 of the blood acts  in other directions  deleteriously.   The right
 composition and relative abundance of separate constituents of
 the blood are  indispensable to the correct physiological action
 of any of the organs.   Hence, we find that indigestion from
 depraved or insufficient gastric and intestinal secretion, almost
invariably attends great inactivity.   What digestion does take
place is so imperfect as still further to deprave the composition
of the fluids, and add to the tendency to organic trouble.   The
liver, pancreas, and  in fact all the glandular apparatus, either
become torpid  merely or depraved in their action.  This indi-
gestion and torpor  of the  abdominal  glands  are sometimes
alternated  with  copious  effusions  in  the  intestinal  canal  and
diarrhea, as we see in chlorosis and other affections of this sort.
              2 
18
    In this  general  depravation, the nervous system suffers its
  share.   Cephalagia, neuralgia,  and neurotic  phantasies  of all
  sorts and of the most distressing character, generally accompany
  this condition of things.   The  nervous symptoms  sometimes
  assume  such  prominence as to  mask for a time—and I am not
  sure  if they  do  not postpone  other—more disastrous evils to
  which the patient  is tending. . Want of exercise  has another
  more direct and positively deleterious influence on the inactive
  organs.   We will be able to appreciate the force and direction
  of this evil influence best, by recurring to examples of extreme
  degrees  of inactivity.   All  of us must have observed the great
  muscular debility with which patients arise from a long confine-
  ment, by serious accidents;  how long it requires for muscles of
  a broken limb to  regain their  wonted vigor, and command of
  the member, and how much the faculties are all obtunded by the
  absolute confinement and inactivity of prison  life.
    It may be stated, I think, without any suspicion of its correct-
  ness, that  no organ can exist without functional action.  They
  are not developed in  animals* of corresponding species  where
  they are not needed.  The fishes of lightless caverns of America
  have no eyes, and yet they  cannot be proven to be different in
. any other respect from  the  fishes  in  the neighboring external
  brooks.   And I  do not hesitate to believe that the sixth gener-
  ation of human beings confined to  an entirely unlighted cavern
  like the Mamoth  Cave,  would produce  blind offspring.    The
  second having less perfect  organs of vision than their parents,
  the third  still greater deteriorations, and so on until the  eyes
  would be merely rudimentary.   We have no examples that I am
  aware, of  any of the higher order of animals ever having been
  submitted to such trial; but I think the inference justifiable,
  and therefore venture to express it.
     The entire inactivity resulting from paralysis is succeeded by
  complete  muscular atrophy—not merely want of energetic
  nutrition from nervous  influence, but structural alteration;-the
  muscles lose their fibrous texture and degenerate  into masses
  of areolar tissue, so that no amount of  stimulus is sufficient to
  cause them to contract.  The probability is this, muscular atrophy
  is one of the greatest obstacles to cure in paralysis. 
19
   We cannot  account for the cure of muscular paralysis by
 electricity upon any other principle  than  its stimulus upon the
 muscular fibre directly, and their increased capacity therefrom.
 The more susceptible and powerful  the muscular fibre,  the less
 nervous force  is necessary to cause contraction.  We  do not,
 cannot suppose for a moment, that electricity or galvanism can
 add to the amount of nervous force, it merely supplies its place
 temporarily, until the disease which  produced the lesion has
 passed by.  Some very valuable practical lessons may be deduced
 from this consideration of the facts as above stated.  The first
 is that there is no danger of beginning with our electrical stimu-
 lation too soon.  The stimulation of the muscular fibres by  the
 local application of electricity is necessary (not only useful but
 necessary) to the preservation of their  capacity to act when the
 nervous stimulus may be  restored to them.  There is no danger
 of exhausting  their  excitability unless we use  it imprudently
 strong.   And  I insist,  that much of the failure resulting from
 a trial of electricity in paralysis arises from neglect to stimulate
 the muscular fibres, until their capacity for action is damaged.
 I am aware that this is not in accordance with the teaching of the
 majority of authors, as I might show by quotations if I had time,
 but I hope the members will pardon me for thus plainly sta^ng
 my convictions.
                  THERAPEUTICAL INFLUENCE.
   It cannot be doubted that exercise, producing as it does such
 extensive physiological and  pathological effects, may be turned
 to therapeutic  advantage.   Its general effects are depurative,
 alterative and  catalytic.   I have  probably shown  sufficiently
 already  the  manner in which it  is  depurative: by  promoting
 secretion and  excretion,  and  thus  casting  out of the  blood,
 through  these  emunctories, such effete substances  as might be
 detrimental by their presence.  I hope it will not be necessary
to dwell on this point to any greater length.  It is alterative  by
being  depurative  and  tonic.   It  changes the  direction and
character of morbid action by equalizing the circulation, sending
the blood with  more vigor through  capillaries in which it has
been  stagnated by  congestion, and depleting  in  a peculiar
manner by secretory evacuation.  In this  last respect we may 
20
instance the good effect a hearty commotion  of  the chest by
laughter has, in producing mucous expectoration and relief from
constriction, that had previously .existed, and the good influence
on some diseases of the skin.   But still another general effect
which I term  catalytic, for want of  a better term, has a great
influence upon the well being of the physical and mental system
of man.  It is a reacting influence of the different constituents
of the  blood upon  each  other, brought about indirectly by
exercise.   Change in organs produces*change in the constitution
of the blood, and thus renders it more adapted to the normal
nutrition of  other organs.   If the muscular  system remains
quiet, the decomposition of certain compounds in the blood con-
taining  its  nutritive principle does not take place.   These com-
pounds  may, and probably do contain, in some chemical or vital
condition of cohesion or attraction, the principle for the Susten-
ance of some other system  of organs, the nervous, I will say,
for  illustration.   But these latter, although present, may not
ba in a state for appropriation until the former  is separated by
the muscular nutrition.  The play of nutritive affinities between
the blood and any of  the tissues cannot be perfect unless it be
good  in all.   If there is a failure anywhere in the great circle
of nutritive assimilation, constituted  by the complete  variety
which make up the whole  system, it  is felt by all more  or less.
Indeed, it is almost certain that the development and perfection
of hematosis depend, after the  chyle is received into the vessels,
upon  the influence of all the  organs  as  the blood  circulates
through  their capillaries.   In  this view of  the  subject, we see
that hematosis is not effected  by themes  enteric glands, lungs
and liver, or any other special set of organs, but is the effect of
the co-operation  of  all the tissues, each  contributing to  the
perfection  of the process, by  abstracting from  and adding to
the mass in the  general round of circulation.   The mesenteric
glands,  no  doubt, impresses upon the  chyle  some  influence in
composition and  change that- is  indispensable.   Their  effect is
not only indispensable but peculiar : it is thrown into the blood,
mixed  and circulated  by the  heart,  passes  into the  lung to
undergo change, which can be effected nowhere  else.   In the
course of its general round it is received into the spleen, where 
                             21

cavernous formation has also a specific effect upon its composition
and fitness for use.  The liver, with its double circulation, con-
tributes another  touch of perfection to  the* changes  already
commenced; thence this fluid carries with it a condition not before
possessed  and acquirable in no  other  organ, and  as has  been
imagined, perhaps the thymus, thyroid  bodies  and supra-renal
capsules, all contribute in their own way their own impressions,
each distinctive and unlike the other; but after all the generally
considered processes  of sanguification are complete,  this blood
would be unfit for all its purposes until it had been  peculiarly
impressed  by the cerebral or nervous,  the muscular and other
tissues.  Now what one of these tissues  produce a state neces-
sary as precedent circumstance to the changes which  succeed in
other points, cannot be said with any degree  of certainty.  But
the stomach must not fail in one small particular, in performing
its (the) first duties in assimilation; the mesenteric glands, the
lungs, the  liver,  all must act just right;  the muscles must act;
there must be cerebral, in fact, every variety of functional action,
or Uhe blood degenerates in composition  and becomes unfit for
perfect support to any one of the series of organs.   When there
is nervous derangement or disease, the  blood  is deranged in
quality and the phosphates are eliminated by the kidneys in more
than ordinary q\>antities, while all the functions are disordered.
If the muscles are diseased, as in rheumatism, acid to an inordi-
nate extent may be discovered in the excretions, while the system
is disordered in every respect.  The kidneys  excrete urea under
muscular  exercise in  larger quantities  than when in  repose.
Sedentary and studious habits give preponderance to the phos-
phates.   I have  been led into this train of reflection in tracing
the mutual influence  of one organ  upon another through the
blood,  to  exemplify  my meaning of catalytic effect  (or  the
decomposing effect) of exercises.   I think it shows the necessity
of the decomposing effect of one organ to the composing influence
of the blood upon others, and  that as every cell selects its own
peculiar substance and prepares the fluid for  another step in
development, so  does  each organ  by selecting its own peculiar
nutritive  properties from  the  blood,  prepare that fluid more
completely than it could otherwise be for the sustenance of other 
22
organs.  Now the general therapeutic effects of exercise in this
direction, I think, will be apparent from the above observations.
We must enforce muscular exercise when practicable at all, as
a conservative measure—a measure to sustain the healthy con-
dition of the well organs.   There is no doubt that many serious
forms of disease  arise from a want of observance of this rule.
Many of the derangements referable  to  the  above explanation
of facts are called sympathetic derangements.   The muscles do
not appropriate  the  substance intended for them, the  blood
retaining it, and  is unfit for the formation of gastric secretion
of a perfect character, indigestion results; the secretions  from
the bowels are slow, costiveness follows, etc.   We cannot  deny
that costiveness and indigestion is the effect of want of exercise,
the only difference is the manner of explaining their connection.
Want  of exercise deranges all the  secretions and  excretions,
they cannot be  healthy under a state of absolute confinement,
and I think the reason is because the blood is changed, or rather
is not sufficiently changed for the perfection of these processes.
The special therapeutic  effects of exercise  are very numerous
and varied, and  depend upon  the kind  of exercise, and  I will
give them more particularly in another place under the head of
special exercise.
   The kinds  of general exercise most in use ai^ carriage, horse
and  foot.  Exercise  has  also  been separated into active  and
passive, but this is  not a strictly correct application of terms,
for if there  is muscular action at all it is  active, and without
such action I should not use the term  exercise  in connection
with it.   Carriage exercise is a very gentle, or may be made
very gentle  exercise.  The only muscular exercise in carriage
riding  is the amount of effort necessary to retain position.  If
sitting and the vehicle is conducted over rough roads and driven
pretty rapidly,  it  becomes very fatiguing on  account of the
large number of muscles called into play, and the frequency of
action necessary to keep  position, and may produce a greater
general effect, depurative  and alterative, than walking.   Horse-
back riding,  however, is justly considered the most profitable,
because  the  most  varied  of  any  of the three  sorts I  have
mentioned.   It  calls into action  a  larger  number of muscles 
23
simultaneously, perhaps, than any other.  The bracing in the
stirrups calls into action all the muscles of the lower extremities,
those of the back, chest, abdomen,  in  fact, the whole trunk,
including the neck,  are employed  in  maintaining  the erect
posture, under the varying relations  of  the  centre of gravity;
while those of the upper extremity are constantly required to guide,
check and otherwise control the animal.   Now all the conditions
necessary to make this  a trying and very fatiguing process is to
have a rough gaited and spirited horse.   On account of the  large
number of the muscles  employed, and the  constant  and active
efforts required to perform the  great diversity of movements,
horseback exercise has more general influence than any  other
with which  I  am acquainted.   It has almost a positive  control
over  deficient secretion and  excretion.   Indigestion, torpor of
the liver and bowels, without organic disease, cannot exist on
horseback.    It  has a  very  happy  effect  upon many  general
affections,  by equalizing the circulation, promoting the secre-
tions generally, and energising digestion and nutrition.  I know
 of no one  means so subversive of cachectic habits,  either with
 or without  organic disease, if it can be borne without immediate
 detriment,  as horseback exercise.   An hour a day, ten miles,
 or any other precise  quantum, will often fail,  when it will
 succeed if used to the extent of endurance.   If capable, the
 individual  should  be on horseback  constantly; at any rate, as
 much as possible.   In consequence of the depurative and robo-
 rant effects,  I look upon  it  as  one of the very best means of
 preventing and even curing in the early stages of tuberculosis.
 But in the  advanced stages of consumption, it is too fatiguing,
 the system has lost its  capability for enduring so much muscular
 action, and of course  it is not  available.   It would be foreign
 to the objects  of this paper  to go into minute detail of the
 applicability of this  kind of  exercise to  all the  diseases  in
 which  it  is  found  to be beneficial.   Exercise  on  foot,  or
 walking, as  a therapeutic and hygienic   measure,  is not  as
 highly appreciated in  this country  as  it is in Europe, particu-
 larly in England.   The  pedestrian  feats of many  English
 ladies  would, if  related,  astonish their   fair sisters of this
 country.   No  doubt  much  of. the robustness  of  frame  and 
24
 beautiful color of the English females depend upon  this salu-
 tary habit of  walking several  miles  every day.   A  little  wet
 weather or  a  bleak wind  does not  prevent  this  practice—it
 would be as inexcusable to neglect the daily walk as the neat
 toilet exercises which always  precede  it.   Walking is, although
 more fatiguing  than riding on horseback,  a less  healthful
 exercise.  It is more fatiguing, because some particular muscles
 support  the main burden of the exertion,  while others are com-
 paratively at rest.   It is less salutary and healthful, because
 so large  an amount of the muscle are  not in action  as on horse-
 back, and  hence the amount of blood change is less;—all  the
 general  effects of exercise, however,  are  to  a greater or less
 extent realized from walking.   It is more available than either
 of the other sorts, because less expensive, and  may be practised
 in less room.  Although the influence is much enhanced by open
 air exercise, yet much valuable results may be  brought about in
 the  sick  chamber by systematizing this kind  of exercise;  and
 in convalescence from acute  disease,  or in some  chronic cases
 that will not bear exposure, we should not forget it.  There is
 also a kind of exercise too that is available to the poor prostrated
 bedridden patient that I doubt not may be advantageously used
 on  certain occasions.  I  allude  to what I  call  static  muscular
 exercise.   It  consists  in  the   voluntary  contraction  of the
 muscular fibres of the limbs, so as to retain them in the position
 they happen  to be  placed.   The patient with  a broken limb,
 who cannot rise  for fear  of displacing the adjusted fragments,
 may thus draw all the fibres of  the sound  limb tense,  and keep
 them so,  or alternately relax  and contract them as he may be
 able to bear it, until all the general effects of muscular exercise
 be produced,  and manifested in the secretions,  excretions, appe-
tite, digestion and good health generally.   I have no doubt that
if patients were rightly instructed and attended to in this respect,
many of the broken down constitutions,  with which patients
often arise from the  effects of severe accidents to the extremities,
would be prevented.  No man  can  appreciate the  powerful
effects of this kind  of  exercise without some experiments upon
the subject.  I have already alluded  to  its  effects upon the
pulse;  it also  induces perspiration, diuresis,  fatigue, hunger, 
 and all  the effects of muscular motion.   In fact, there is more
 danger of  over exerting the muscles in  this way than walking
 or riding, for in the static exercise of the muscles all of these
 organs are acting  at  the same time; in walking, a part of the
 muscles of the leg carries the foot forward, while those on the
 posterior part are relaxed and  resting; so soon as the foot is
 planted these muscles contract, and  those on the anterior part
 of the leg relax.   And thus they alternately relax and contract,
 resting half the time.  It will be readily experienced that we
 cannot keep all the  muscles of a limb in a state of rigid con-
 traction but a very short time.  The larger number of muscles,
 the greater the general effect.   No man can hold all the muscles
 of the lower extremities in a state of forcible rigidity for two
 minutes, without blowing and sweating quite as much as  if run-
 ning  or  walking  rapidly.  It may  seem  probably,  at least,
 impracticable  to apply this  kind of exertion for hygienic  or
 therapeutic purposes, but certainly many patients are so situated
 that they  cannot  take any other sort,  and their health must
 suffer.  In these cases,  I am satisfied, much good can be done
 in preserving and  promoting energy of function in all the more
 essential organs by this static mode of affecting them.  Besides
 these sorts of  what may be called general exercise, because not
 necessarily confined to any set of  muscles, there is what  may
 be called special exercise, having reference to some part of the
 system;  thus, by exercising the muscles  of  the arms and chest,
 it  is expected  that the  lungs  will  be expanded  beyond their
 former size; in exercising the abdominal, we may promote the
 action of  the  alimentary canal and quicken  digestion;  by
 dancing,  we can enlarge  and develop the muscles of  the  hips
 and legs; by fencing  and boxing, the arms, and  so on.  Much
 may no doubt be effected in this way, which may be made useful
under certain circumstances.  Gymnastics, as practised by skilful
 teachers, is designed to be of general and special usefulness.
  Although every studied motion and act has a special reference
 to some  part  of the  body  or  system of organs, they  are so
numerous and  so  skilfully designed, as  to have a developing
effect upon the muscular system as a whole, by operating upon
each part successively, while they have the depurating, excretory, 
                             2b*

alterative and  catalytic  effects  that  are  produced by general
exercise.  All young persons, who are too indolent and proud to
work, and all others whose occupation  is deficient in exercise,
should avail  themselves  of this, as an excellent means of pro-
moting their  health.   Occupations often involve the exercise of
only a part of the muscular systems, and hence may be used
under certain circumstances, therapeutically, for changing the
current of circulation and strengthening parts of the organism;
so that we should  never lose  sight of the excellent effect of a
change of employment that may be brought about under certain
contingencies.  And I cannot but think that exercise by some
employment,  with  the double object of  pecuniary and hygienic
good, is more effective when properly adapted to the case, than
merely to take  exercise for our health.
  I  cannot do  more than merely  allude to this  view of  the
subject now on  account of the limit of this paper.  I may say
in a  general way in conclusion, that  exercise in acute diseases,
particularly inflammations, is scarcely ever applicable, absolute
rest  being the rule, and that it is to chronic cases to which it is
most appropriately adapted.   Acute  cases, in fact, are nearly
all injured by the arterial excitement which accompanies it, but
after the acute symptoms to some extent have subsided, exercise
will promote  healthy action and assist in repairing the damage
resulting from the force of the attack, and should be prescribed
with as much care and  discrimination  as the  more medicinal
part of  treatment.  This will often be found as essential to the
welfare of our  patient as any other remedial measure.   Many
cachexia, no  doubt, grow out of the anemic and deranged con-
dition of the system resulting from the progress of acute diseases,
and  might be  prevented  by  this and  other roborant  means
during convalescence.  Great care, however, will be necessary
to avoid relapse from too much arterial excitement; the  return
to exercise must be gradual,  and cautiously watched.   There
is probably no chronic disease  in which exercise may not be
employed as  a  remedy, and I think it is the  principal  curative
means in many of  them.  On the lungs, exercise has a peculiarly
good influence.  They of course  partake in the general cata-
lytic operations, while they grow and enlarge  from the increased
demands made  upon them for oxygenation of a greater amount
of blood. 
S>-
1951!