OZONE, 
AND ITS 
RELATIONS TO THE PUBLIC HEALTH. 
V BY 
J. D. PLUNKET, M. D., 
Of Nashville, Tennessee. 
MEMBER OF THE STATE BOARD OF HEALTH, AND ITS 
COMMITTEE ON OZONE. 
REPRINTED FROM THE SECOND REPORT OF THE STATE BOARD OF HEALTH, 
I (January 1, 1885.) — OZONE, AND ITS RELATIONS TO 
THE PUBLIC HEALTH. 
Ozone is a peculiar variety of oxygen, distinguished 
from ordinary oxygen by its greater weight, its peculiar 
and somewhat chlorous smell, its intensely active ox- 
idizing powers and the ease with which it passes into 
common oxygen. Ozone, as it appears in the atmos- 
phere, is in variable amount, differs in degree according 
to height, locality, temperature, electricity, etc. Mr. A. 
Beechan says, “ it is more abundant on the sea coast than 
inland, in the west than in the east of Great Britain, in 
elevated than in low situations, with southwest than with 
northeast winds, in the country than in towns, and on the 
windward than on the leeward sides of towns.” And Moffat 
states it is found in greater proportions when the mean 
daily temperature and the dew-point temperature are above 
the mean and the readings of the barometer are decreasing. 
From the records of the Scottish Meteorological Society, 
we find it “ most abundant from February to June, when 
the average amount is 6, and least from July to January, 
when the average is 5.7. The maximum, 6.2, is reached in 
May, and the minimum, 5.3, in November.” Comment- 
ing upon this, remark is made that “ thus the maximum 
period occurs when evaporation is greatest, and the min- 
imum when the condensation of aqueous vapor is great- 
est, a result in accordance with the conclusions arrived at 
by Dr. Berigny and M. Houzean. It thus also appears 
that it is most abundant where electricity is produced, and 
least so, or entirely wanting, where electricity is in least 
quantity, and where there is much decaying vegetable and 
animal matter.” Ebermeyer says it is found most abun- 
3 4 
OZONE. 
dant in the air of open fields and in places of great atmos- 
pheric moisture. In the forests more is found in the upper 
strata of air, among the branches, than near the ground, 
owing, doubtless, to the absorption which occurs in the 
process of decomposition. According to Dr. Cornelius 
Fox the sources of ozone are—“ The oxidation of metals, 
the decomposition of rocks, the germination of seeds, the 
growth of plants; the collision between air-currents of 
different degrees of humidity, proceeding from opposite 
quarters with one another, or with the earth; the evap- 
oration which is continually proceeding from saline 
fluids, such as oceans, seas and lakes; the dashing 
and splashing, the smashing and crashing of the rest- 
less waves on the rocky coast—are all concerned in the 
simultaneous development of electricity and ozone.” Kedzie 
says that ozone is to be “ found where water by any 
means is ‘ pulverized/ e. g., in the neighborhood of 
waterfalls,” and in commenting upon this fact remarks 
that “this may possibly be explained by the fact, 
now well established, that ozone is soluble to a small ex- 
tent in water (J of 1 per cent.), and where water is thus 
converted into spray this dissolved ozone may be liberated.” 
And he further adds: “ It may at last be found that the 
delight which civilized man has ever taken in the thunder- 
ing of the ocean surf, the roar of the waterfall, or the 
silvery tinkling of the fountain, has a deeper significance 
than the gratification of an esthetic taste, and that our sense 
of the beautiful is thus happily correlated with an import- 
ant condition of bodily health.” 
The chemist has never as yet been able to isolate ozone. 
In its sensible properties it is a colorless gas, having a 
peculiar odor of phosphorus like that perceived during the 
passage of an electric spark, which caused Van Marum, 
who was the first to notice it in 1785, to describe this odor 
as “ the smell of electricity,”—he believing electricity to be 
a material substance. This odor is so powerful that it is 5 
OZONE. 
said that one part in a million of air can be distinguished 
by the sense of smell. It is one of the most powerful ox- 
idizing agents known, oxidizing silver, mercury, iodine 
and many other substances immediately. It corodes cork, 
paper, animal membranes, caoutchouc, and other organic 
substances. 
It is nature’s great disinfectant and deodorizer, uniting 
most readily with the gases which arise from decaying 
vegetable and animal matter, and by depriving them of 
their noxious qualities, serves as a great purifier of the air. 
Its importance arises from its intense activity rather than 
its amount, for the maximum quantity of ozone in the air, 
Howzean informs us, never exceeds ? oVoqtt of its bulk, 
and often is entirely wanting. 
What relation this intensely active and exceedingly in- 
teresting agent sustains to animal life, is the aspect of the 
subject which must interest us most, and when the addi- 
tional fact is stated that the influence which ozone exerts 
upon health and disease is still an undetermined problem, 
it cannot fail to prove an active stimulus to our efforts in 
aiding, so far as possible, by the accumulation of data and 
otherwise, tfye elucidation of a question which apparently 
promises so much. Ozone, in its effect upon the mucous 
membranes, especially of the respiratory passages, is that of 
a powerful irritant, when breathed in any concentrated 
form, which fact led to the suggestion of its possibly being 
in some way connected with, if not the immediate cause of, 
epidemics of influenza and catarrhs. Schcenbein observed at 
Berlin, during an epidemic of influenza, a considerable 
quantity of ozone in the atmosphere. Dr. Pietra-Santa 
has also shown that when influenza prevails the ozone- 
papers show lively reactions. Prof. Charles N. Hewitt, 
of Minnesota, in a paper read before the American 
Medical Association in 1871, says: “ The peculiar at- 
mospheric condition which is the cause of our epi- 
demic influenza is now attracting deserved attention, 6 
OZONE. 
and it is hoped that the recent offer of a prize by the State 
Medical Society may result in investigations of practical 
value. This much is known: that when influenza is 
markedly epidemic, zymotic diseases diminish in severity, 
become less frequent, and disappear. Though as yet no 
sufficient tests have been used, the majority reporting 
(judging from its action on 1 civic miasm,’ which seems that 
of an oxidizing agent, and from reports of its study else- 
where), believe it to be ozone.” A residence among the 
balsamic odors of the pine has long been esteemed of ben- 
efit to the pulmonary invalid, which practical fact finds 
ready scientific explanation in the statement made by Dr. 
Schreiber, of Vienna, that “the turpentine exhaled from 
pine forests possesses, to a greater degree than all other 
bodies, the property of converting the oxygen of the air 
into ozone.” Dr. C. Dennison, of Colorado, says “ that 
the excess of ozone noted during the spring months on the 
plains came proportionately late in the season the higher 
up the mountains the observations were made.” This state- 
ment, no doubt, will be fully confirmed by the recorded ob- 
servations of ozone now being made in Tennessee, regarding 
the valleys as compared with the plateau of the Cum- 
berland mountains of our State, which may serve as a 
profitable indication to the invalid, the delicate and over- 
worked, of the special advantages of going into yet higher 
regions during the progress of the summer season, where, con- 
sonantly with the increase of ozone, can be enjoyed the cooler 
temperature and purer atmosphere which elevation always 
insures. 
Beside diseases of the nose, throat and pulmonary struc- 
tures, other maladies have been suggested as in some meas- 
ure due either to the presence or absence of ozone in the 
atmosphere, or aggravated or mitigated by it: for instance, 
Billard, Wolf, Boeckel and Strambes agree that the cholera 
in Strasbourg, Berlin and Milan coincided with the absence 
of ozone, and that it reappeared on the decline of the dis- OZONE. 
7 
ease—an important observation to confirm, should cholera 
visit Tennessee during the approaching summer, as is now 
apprehended by many of the best informed it may. 
Hon. Frank H. Mason, United States Consul at Mar- 
seilles, France, in an interesting report to the Depart- 
ment at Washington, D. C., bearing date of September 
30, 1884, upon the recent epidemic of cholera which oc- 
curred there, under the sub-heading, “ Some Teachings of 
the Epidemic,” makes the following statement: “ It is now 
a well established fact that the presence or absence of ozone 
in the atmosphere has a marked effect upon choleraic con- 
ditions. 
“ It was noted early in the present epidemic that there 
was a marked deficiency of ozone in the atmosphere of Mar- 
seilles, and means were adopted to supply this deficiency at 
the Pliaro Hospital, in this city, by the usual means of an 
electrical apparatus. 
“ The process of negatively electrifying the oxygen of 
the air on a sufficiently large scale for practical sanitary 
purposes is always difficult, but sufficient was done and ob- 
served in this direction to fully establish the following facts: 
“ 1. That the whole period of the cholera epidemic has 
been marked by a notable deficiency of ozone in the at- 
mosphere of Marseilles. 
“ 2. That in the wards of the Pharo Hospital, where arti- 
ficial ozone was provided, the death-rate was considerably 
diminished. 
“ 3. That the days of greatest fatality in respect to the 
number of both new cases and deaths were those during 
which the proportion of natural ozone in the air was small- 
est. 
“4. That the setting in of a southwest wind, which, al- 
though warm, brought an increase of ozone to the local 
atmosphere, was, in every instance, followed by an immedi- 
ate and marked decrease in the death rate and the number 
of new cases reported.” 8 
OZONE. 
Cholera has appeared twice in epidemic form at Fort 
Riley, in Kansas, and Dr. W. A. Hammond is quoted as 
authority for saying that while the epidemic continued at 
that post, the air was dry and contained no ozone, the oc- 
currence of a very severe thunder storm put an end to the 
epidemics in both instances, and ozone at once reappeared 
in the atmosphere. 
The wonderful oxidizing power of ozone has caused its 
artificial production to be suggested for ordinary disinfect- 
ing purposes. On November 21, 1878, I had the honor of 
reading a paper before the American Public Health Associ- 
ation on “ The Disinfection of Sewers by Ozone,” suggesting 
a simple and cheap devise for its manufacture and applica- 
tion in “ the disinfection of sewers and other sources of 
mephitic gases.” In this connection, Dr. Fox in a late work 
suggests that “ozone should be diffused through fever-wards 
sick-rooms, the crowded localities of the poor. Its employ- 
ment is especially demanded in our hospitals, situated, as 
they mostly are, in densely populated districts, where the 
atmosphere is nearly always polluted by re-breathed air, 
decomposing substances and their products, and where no 
ventilation can be fully effective.” Continuing, he further 
says : “ If practicable, it would be highly advantageous to 
direct streams of air, artificially ozonized, into the fever 
and cholera nests of our towns.” Ozone may be easily 
disseminated through public buildings, theaters and other 
confined atmospheres, where numbers of people are accus- 
tomed to assemble, in order to maintain the purity of the air. 
Curious and interesting as is the subject of the pres- 
ence and effects of ozone in its manifold applications, the 
obscurity which envelops still the whole subject requires 
yet many thousands of accurate observations before defi- 
nite deductions can be profitably attempted. Appreciating 
fully this fact, so far as ozone bears relations to human 
health and disease, the public health men of Tennessee 
have been long anxious to see inaugurated some plan by 9 
OZONE. 
which ozone observations could be secured regularly by 
competent observers in different places throughout the State. 
With this view, the Nashville Board of Health acted form- 
ally and early, as will be seen from the following extract 
taken from the report of J. Berrien Lindsley, M. D., 
Health Officer, as published in the Third-Report of the 
Nashville Board of Health, 1878: 
“ At a meeting of the Board, held June 20, 1876, it was, on mo- 
tion of Dr. J. D. Plunket, 
“ Resolved, That the meteorological observations made by the 
United States Signal Service here and at other points are of the 
greatest value to the physician, as well as to the agriculturist and 
merchant. 
“ Resolved, Also, that the value of the observations here, in a san- 
itary point of view, will be greatly increased by proper registrations 
of the variations of ozone in the atmosphere. 
“ Resolved, That the Director of the United States Signal Service 
be petitioned to supply the Nashville station with the necessary 
means for such registration. 
“ Adopted, and the Health Officer was directed to transmit a 
copy of them to the Department at Washington, D. C. In response, 
the following was received : 
“War Department, Office of the Chief Signal Officer, 
Division of Telegrams and Reports for the Benefit 
of Commerce and Agriculture, 
Washington, D. C., July 10, 1876. 
“ J. Berrien Lindsley, M. D., Health Officer, Nashville, Tenn.: 
Sir :—By direction of the Chief Signal Officer of the Army, I 
have the honor to acknowledge and answer your communication of 
the 6th inst., communicating resolutions of the Board of Health of 
Nashville relative to special observations for the benefit of the pub- 
lic health. 
This has frequently been considered by this office. What it does 
in the domain of climatology is in addition to its regularly defined 
duties, and it is quite certain that to enter upon the kind of obser- 
vations to which you refer would require a very liberal construc- 
tion of the laws and orders relating to this service. It would, how- 
ever, afford this office satisfaction to enter upon the additional field 
of usefulness, if authorized and provided with facilities, but every 
new observation would require more money and more force, whereas 
it seems probable that Congress will diminish both the money and 10 
OZONE. 
force heretofore allowed, thus rendering necessary an abandonment 
of work now performed. The proper course for the Board of 
Health would be to address to Congress resolutions showing the 
importance of increasing the appropriations and force of the Signal 
Service, and send them to the proper Senators and Representatives, 
also one copy to this office, that it may be referred to. The present 
resolutions, however gratifying as showing the appreciation of the 
work of the service, are not practically useful for the immediate 
.object the Board has in view, as the facilities must be given by 
Congress before they can be used to comply with the request of the 
Board. Respectfully yours, 
Garrick Mallery, 
Captain and Brevet Lieut. U. S. A., Acting Signal Officer and 
Assistant. 
“ Acting upon the above, at a meeting of the Board held July 20, 
inst., it was unanimously resolved, that the following memorial be 
sent to the Senators and Representatives in Congress from Tennes- 
see: 
“ The Board of Health of the City of Nashville do hereby respect- 
fully memorialize the Senators and Representatives of the State of 
Tennessee in Congress assembled, as follows: 
“Whereas, By an Act of Congress, approved February 9, 1870, 
it was made the duty of the War Department to make, register and 
publish, by telegraph and otherwise, an extended series of meteor- 
ological observations; and, 
“ Whereas, The United States occupy climates and areas pecu- 
liarly fitted for solving the great problems connected with epidemics 
and public health, as well as intricate questions connected with the 
physical sciences which Franklin and Morse did so much to de- 
velop ; and, 
“Whereas, This invaluable series of observations is utterly 
beyond State and individual effort, and yet is alike beneficial to all 
the individuals and States composing the Union : 
“ Therefore, we do earnestly hope that your influence and vote 
will be so used as to increase and extend, and not cripple the singu- 
larly beneficent and peaceful workings of this small portion of the 
national army. 
What Congress did regarding this Bureau was, in a 
word, to let it alone—no increased facilities were allowed, 
it, and up to now, as an organization, it has attempted no 
ozone observations that we are aware of. 
Dr. Albert C. Ford, United States Signal Service ob- OZONE. 
11 
server stationed at Nashville, upon the suggestion of the 
Chairman of the Committee on Climatology of the Local 
Board of Health, began the taking of ozone observations 
in the spring of 1877, but soon after, in consequence of 
failing health, abandoned it. These, it is believed, were 
the first ozone observations ever made in Tennessee. No 
further effort was made, so far as we are informed, to ascer- 
tain the amount of ozone in the atmosphere of our State 
until the fall of 1884, when a special Committee on Ozone 
was raised in the State Board of Health, and upon the re- 
quest of its Chairman, L. N. Jesunofsky, United States 
Signal Service observer, stationed at Nashville, began on 
October 1,1884, to make regularly two daily observations on 
ozone. With the view of obtaining similar observations 
throughout the State, the following correspondence indi- 
cates what steps were taken and progress made : 
Nashville, Tenn., September 29,1884. 
Hon. A. J. McWhirter, Commissioner of Agriculture, Statistics 
and Mines, and Director of State Weather Service, Nashville : 
Dear Sir—Having watched with much interest and pleasure the 
practical workings of the State Weather Service, as organized by 
you throughout Tennessee, I now, in behalf of the State Board of 
Health, request that you take one step further in advance, and add 
one other column to your present form for reports, in which shall 
be recorded the tri-daily observations of ozone, as may appear at 
the different stations in the State. 
Ozone, as you know, is Nature’s great deodorizing and purifying 
principle that oxidizes the emanations from decomposing animal and 
vegetable substances, with which the air is unceasingly being con- 
taminated, thus rendering them innocuous, and fitting the atmos- 
phere for the further sustenance of animal life. 
An agent, then, of such amazing power, and present in such va- 
riable amount in the medium which envelops us every moment of 
our lives, cannot, it would seem, be other than most significant in 
its influence upon public health. 
It is in this relation that the information sought is most desired, 
for, as yet, we have not a sufficient amount of carefully observed 
fact to serve as a basis for any generalization of the special relations 
of ozone to disease. 12 
OZONE. 
To the end of supplying this great want, by having the facts in 
regard to ozone in Tennessee gathered up and collated, and thereby 
serve indirectly as an inspiration to other States and communities 
to do likewise, this communication finds its apology j for then, by a 
careful and conscientious comparison of these facts, with the re- 
gional and seasonal history of disease, we may be enabled to arrive at 
conclusions which shall be more than unfounded assertion or imag- 
inative hypotheses. 
Should you be pleased to co-operate in the manner suggested, this 
Board will furnish to all observers whom you may designate, the 
means by which the observations can be made, accompanied by such 
instructions as may be necessary for the easy comprehension of any. 
I am, sir, very respectfully and truly yours, 
J. D. Plunket, M. D., 
Chairman of Committee on Ozone of State Board of Health. 
Nashville, Tenn., October 6,1884. 
Dr. J. D. Plunket, Chairman of Committee on Ozone of State 
Board of Health, Nashville: 
Dear Sir—Your communication of September 29th, asking the 
co-operation of the Weather Service Department of this Bureau, 
in getting the observations of ozone throughout the State, has,been 
received. 
This Bureau will, at all times, cheerfully and heartily co-operate 
with the State Board of Health in anything pertaining to the wel- 
fare of our State and the advancement of the physical or material 
interests of its citizens. 
Your suggestions regarding the mode of taking the observations 
will be presented to our voluntary observers, and their assistance 
invoked in the work. 
Very respectfully yours, 
A. J. McWhirter, 
Commissioner, and Director State Weather Service. 
In due time notice was received from the Director of the 
State Weather Service that each observer of his depart- 
ment entered heartily into the request, and upon receipt of 
material and instructions, they would cheerfully begin the 
work. At once there was prepared and forwarded, through 
the office of the Director of the State Weather Service, to 
each observer, a copy of the following : OZONE. 
13 
INSTRUCTIONS FOR 
MAKING AND RECORDING OZONE OBSERVATIONS, 
Issued to the volunteer observers of the Tennessee AVeather Service 
BY THE STATE BOAKD OF HEAETH. 
1st. For the present, only two observations in each twenty-four 
hours are called for, viz.: a “ Day Observation,” to be taken from 7 
A. M. to 2 P. M., and a “ Night Observation,” to be taken from 9 P. 
M. to 7 next morning, and recorded in the line of report for the day 
on which the test paper was put out. 
2d. The observations are taken by means of Schoenbein’s test- 
paper, and the result determined by comparing the test-paper em- 
ployed with the ozone-scale, which, in each instance, must be that 
furnished by the State Board of Health. 
3d. Each observer is requested to give timely notice of the ex- 
haustion of his supply of test-paper, that no break in the observa- 
tions may occur, and also to preserve the stock of test-paper in a 
closed bottle or jar, in a dry and dark closet, because sunlight will 
form ozone and color the paper so as to destroy its value as a test. 
Colorless test-paper only must be used in measuring ozone, and it 
should be exposed where it will not be subject to action of sul- 
phurous acid gas, or very near where coal is burned. Even the 
fumes of burning sulphur from a single match, held near the test- 
paper may bleach it after having been colored by exposure. 
4th. In making an observation, take a single strip of the test- 
paper furnished you, dip one-third of the paper in pure water, and 
pin it up in a place screened from direct sunlight, but freely ex- 
posed to the air, arid diffuse daylight. An ordinary spring clothes- 
pin, properly fastened in position, is a convenient article to hold the 
test-paper during the exposure. After exposure for the time stated 
above, dip the paper in clear water, immediately compare it with 
the ozone-scale, and enter in the proper column of report the figure 
on that portion of the scale which most nearly corresponds in color 
with the test-paper used. If there is no discoloration of the test- 
paper, no ozone is present, and a cipher should be entered on the 
record for that observation. 
5th. In deciding the amount of ozone for any observation by com- 
parison of the test-paper with the ozone-scale, the prevailing color 
of the test-paper should be taken, and not the exceptional spots or 
streaks. The observation should be made and recorded from the 
side of the test-paper most darkly colored, whether front or back. 14 
OZONE, 
Also a copy of the lithographed u ozone scale” which is to 
be found upon the following page, and a sufficiency of test- 
paper, prepared after the formula of Schcenbein, to last each 
observer for four months. Observations were begun sim- 
ultaneously upon December 1, 1884, and at this time there 
are twenty-eight observers actively engaged in making 
ozone observations in Tennessee, whose names and post- 
office addresses are as follows : 
Geo. W. Robinette, Quarter, Claiborne county. 
Jno. A. Cody,* Knoxville, Knox county. 
Foster Clarke, Maryville, Blount county. 
David Hart, Careyville, Campbell county. 
S. E. Franklin, Sunbright, Morgan county. 
J. T. Cowden, Grief, Bradley county. 
B. L. Goulding,* Chattanooga, Hamilton county. 
T. L. Denny, Cookeville, Putnam county. 
W. K. Patterson, Jr., McMinnville, Warren county. 
S. P. Fergusson, Riddleton, Smith county. 
Chas. F. Vanderford, Florence Station, Rutherford county. 
L. N. Jesunofsky,* Nashville, Davidson county. 
Prof. J. M. SafFord, Yand. Univ., Nashville, Davidson county. 
J. A. Laughlin, Hurricane Switch, Maury county. 
Rev. C. F. Williams, Ashwood, Maury county. 
Samuel Stewart, Clarksville, Montgomery county. 
W. J. Inman, Kingston Springs, Cheatham county. 
Frank Winship, Pulaski, Giles county. 
Sam’l Donaldson, Dickson, Dickson county. 
Dr. Cicero Buchanan, Waynesboro, Wayne county. 
H. R. Hinkle, Savannah, Hardin county. 
Dr. M. D. L. Jordan, Milan, Gibson county. 
A. S. Currey, Trenton, Gibson county. 
E. P. McNeal, Bolivar, Hardeman county. 
Louis Hughes, Dyersburg, Dyer county. 
D. B. Cummins, Somerville, Fayette county. 
Dr. T. W. Roane, Covington, Tipton county. 
D. T. Flannery,* Memphis, Shelby county. 
A number of other names are expected to be added to 
this list soon. 
The observers will make their reports to the Director of 
* U. S. Signal Officers. 1 
6 
®2©K1E 
9 
l 
3 
8 
Jt 
9 
J 
io 
Goes & Quensel,Lith.Chicago OZONE. 
15 
the State Weather Service, and he will embrace the same in 
tabular form in the monthly printed report issued from that 
office. Thus will be accumulated and preserved the data 
regarding ozone in Tennessee, which will, at the proper 
time, be analyzed, arranged and reasoned upon by your 
Committee on Climatology with the view of obtaining, if 
possible, practical deductions, especially so far as ozone 
may appear to be related to questions affecting the public 
health. 
The Committee on Ozone had reprinted and distributed 
among the observers of the State Weather Service, and 
others interested in the subject, the two following instruct- 
ive and valuable papers, the one by Dr. Mulvany, and the 
other by Dr. Nicholson. 
OZONE IN NATURE* 
ITS RELATIONS, SOURCES AND INFLUENCES. 
A Paper read before the British Meteorological Society, June 16, 1880. 
BY J. MULVANY, M. D. R. N. (ENGLAND.) 
Ozone, since its discovery by Schoenbein, has been to the 
scientific world the subject of incessant study and observa- 
tion; by medical men especially it has been regarded with 
the deepest interest, for experiment has shown artificially 
prepared ozone to be endowed with great energy of action, 
and to be adapted by its physical atributes and chemical 
affinities to play a very important part in the chemico-vital 
processes of the system, and in the purification of the at- 
mosphere. And as it was seen to stimulate the respiratory 
and circulatory organs, and when inhaled in excess, to irri- 
tate the mucuous tract over which it passed, and moreover 
to be readily absorbed by the blood, in which it liberates 
* Michigan State Board of Health, Report 1880, page 277. 16 
OZONE. 
oxygen, checks incipient putrefaction, and replaces it by 
restored coagulability, and to so elevate in the scale of oxi- 
dation the chemical formula of the products of retrograde 
metamorphosis, as to render them more facile of elimina- 
tion, atmospheric ozone came to have ascribed to it the 
most varied offices and influences, prophylactic, sanitary, 
morbogenetic, etc. But the part it plays in the economy, 
and how far it ministers to health or promotes disease, 
should be determined by observation alone. And as it is 
rarely met with dissociated from meteoric and other subtle 
agencies which often are sufficiently powerful to modify the 
extent of its appreciability or to disturb the functional har- 
mony of the system, a careful elimination of the effects of 
these one by one is obviously necessary for the differentia- 
tion of its action (per se). For the acquisition of such an 
accumulation of data as this requires, the naval medical 
officer has peculiar facilities. In the observations from 
which the present report is epitomized are embraced the 
varied conditions of climate met with between the Dogger- 
bank on the north, Madagascar and the Falkland Islands 
on the south, and from 96° long, west to the same number 
of degrees east, and the modifications which ozone under- 
went from cold, heat, humidity, pressure, geographical 
position, configuration, soil, contiguity to a desert, a jungle, 
or a marsh, etc.; also, the corresponding sanitary condi- 
tions on shore and afloat. As the investigation of its 
effects may be advantageously preluded by that of its rela- 
tions, I will proceed to the consideration of these latter, 
commencing with temperature. 
Temperature.—From experiments in the laboratory, 
when a high temperature is seen to break up the pecu- 
liar grouping of the molecules of oxygen which con- 
stitutes ozone, and restores them to their bulky and less 
active state, it has been supposed that a much heated con- 
dition of the atmosphere is inimical to ozonization, and 
hence probably it has come to be axiomatically formulated, OZONE. 
17 
that the curve of the ozone is in the inverse ratio to that 
of the temperature. Strictly speaking, this rule holds good 
where a high temperature with a minimum humidity ob- 
tains ; but this is too seldom witnessed in nature to consti- 
tute a rule; so narrow is its applicability that it might 
rather be classed as an exception. For as the atmosphere 
becomes rarified by heat its capacity for taking up and 
holding water in a state of vapor is correspondingly ex- 
alted, and consequently a high temperature, except under 
peculiarities of locality to be hereafter alluded to, is always 
associated with a high humidity, and humidity is favorable 
to ozone. But, regarding temperature alone, it will be 
seen from the following table that the temperature of the 
atmosphere as met with in nature bears no relation to its 
ozonic condition: 
DATE. 
Place. 
Temperature in Shade. 
Minimum. 
Maxi- 
mum. 
Me- 
dium. 
Mean. 
January, 1867 ... 
Lake Erie 
14° below zero. 
16 
32° 
9° 
2°.5 
January, 1868... 
“ “ 
27 
5.5 
2.5 
“ 4 • 
31 above “ 
26 “ *’ 
52 
41.5 
3.0 
March, 1870 
Harlar Hospl., Heaths 
61 
41.5 
2.0 
August, 1872 
Mozambique 
70 “ 
90 
80 
1.3 
May, 1872 
78 “ 
88 
83 
9.5 
November, 1373 
Trincomalee. Ceylon.. 
75 “ 
86 
80.5 
10.0 
September, 1871 
Persian Gulf 
83 “ 
104 
90 
7.5 
Humidity.—When a high humidity accompanies a high 
temperature, the rule, with many exceptions, however, is 
that ozone is also high, and with a similar temperature and 
a low humidity ozone is scanty. This is illustrated by the 
following figures: 
DATE. 
Place. 
Temperature. 
Humidity. 
Ozone. 
Min- 
imum. 
Max- 
imum. 
Per 
Cent, of 
Satura- 
tion. 
Vapor Tension. 
October, 1865 
Santa Maria... 
78 
85 
77 
0.723 in. Mercury 
5 
August, 1871 
Persian Gulf... 
87 
114 
79 
1.223 
6 
July, 1873 
70 
84 
78 
0 StU “ 
g 
May. 1873 
Muscat,Ar’bia 
94 
99 
28 
0.514 
a tracfr 
September, 1872 
Madagascar ... 
72 
97 
51 
0.570 
2 
January, 1877— 
Falkland Isl’s 
33 
61 
74 
10 18 
OZONE. 
Than this relation of ozone to heat and humidity, nothing 
is more calculated to impress us with the benignity and 
prescience of the design which causes an augmentation of 
ozone, when for the maintenance of a pure atmosphere it 
is most required, that is, under the conditions of heat and 
humidity in which organic compounds are most unstable 
and putrefy with the greatest rapidity. The association of 
ozone with vapor in a high degree of tension, though not 
definite in its relation, is nevertheless so constant that 
whatever tends to augment the latter will have a similar 
effect on the former. This is well exemplified in the case 
of winds. 
Winds.—The hot, dry winds that sweep over the arid 
rocks’of Beloochistan, or the thirsty sands of Arabia, rarely 
contain more than a mere trace of ozone when they arrive at 
the seaboard. In the Mozambique Channel, which the 
southeast trade winds reach after having their moisture 
wrung out of them by the high central plateau of Mada- 
gascar, ozone is very scanty indeed. At Trincomalee, 
during the southwest monsoons, which reach it after being 
filtered through the jungle, a great paucity of ozone is ob- 
served in the lower atmospheric strata. But on the con- 
trary, wherever the breeze reaches after sweeping over a 
large tract of sea, ozone and humidity are usually abund- 
ant. Hence, it appears to be through the nature of the 
surface over which they blow that winds influence the 
ozonic condition rather than by their force or direction. 
Area.—The area over which winds pass, if homoge- 
neous, tends greatly to augment or diminish ozone, water 
producing the former effect, land the latter, the difference 
between the west and east coasts of Mahe, in the Seychelles 
Islands, being one to two degrees less on the leeward side. 
In passing through the Bay of Bengal, January, 1874, with 
the northeast monsoon blowing, I got at the port of de- 
parture, Trincomalee, the maximum shade; at the Anda- 
man Islands (Port Blair), it amounted to only 2; and at OZONE. 
19 
Rangoon, or the embouchure of the Irrawaddy, it barely 
reached 1. 
Clouds are favorable to ozone. In the Indian Ocean, 
where, during monsoon weather, heavy murky piled clouds 
are often met with, the atmosphere is as a rule strongly 
ozonized; whereas, when the sky has been bright, blue, 
and cloudless for a week, it usually averages 1.5 to 2. 
Atmospheric Pressure, humidity apart, does not ap- 
pear to exercise any influence whatever over the ozonic 
condition ; but taking 29.90 for the intra and 30.00 for the 
extra tropical standard, the greatest abundance coincides 
with the readings below these. 
Rain sensibly augments the ozonic condition; if there 
have not been a trace of coloring for several days a single 
shower is often observed to effect an immediate coloration. 
I once observed this under circumstances entirely unique. 
On the passage to Seychelles, in June, 1873, there was an 
abundance of ozone from a few days’ sail off the Arab 
coast to within a short distance of the Equator. I did not 
observe the faintest trace of it during the 18th, 19th and 
20th, although the sky was cloudy, the air hot and humid, 
and the wind high and squally; but during the night of 
the 20th it rained heavily in showers, and the next morn- 
ing the test-slip was colored to the utmost. As we had 
during the period of negation crossed the “ Line,” it struck 
me that the peculiarity of the negation might be owing to 
an antagonistic influence being exercised in the equatorial 
belt by the horizontal magnetic force of the earth, but sub- 
sequent experience showed this conjecture to be erroneous. 
It, however, led me to investigate the relative abundance 
of ozone in the north and south latitudes, but my data are 
not sufficiently copious to admit of deductions. During 
250 days south of the Equator in the Eastern Hemisphere, 
the ozone averaged 3.5, and during 450 days north of it, 
6.5. Since then I passed over two years south of the 20 
OZONE. 
Equator, in the Falkland Islands, and never found the 
ozone under 10. 
Squalls.—A squall without rain produces a very slight 
degree of coloration, but the increase resulting from a rain- 
squall is decided. A thin steady mizzle of a whole day’s 
duration will not show more color than a strong rain-squall 
of two hours. This led me to believe that the 'phosphores- 
cence of the tropical seas might be a source of ozone, and 
that the difference between the thin mizzle and the smart 
shower might be owing to the greater momentum of the 
latter penetrating the sub-surface waters and agitating the 
myriads of noctiluca which have their habitat there, and 
thus cause them to light up their tiny lamps and thereby 
generate ozone; but I failed to corroborate this by experi- 
ment, and subsequently I found reason to believe that rain 
simply acts as a vehicle, and that the difference in effect 
between the mizzle and the smart shower consists in the 
latter coming from a greater height—but I will return to 
this presently. 
Altitude.—When, from any cause, the ozone of the 
lower atmospheric strata gets used up, that from the higher 
does not appear to diffuse readily into its place, and hence 
it occurred that I was often able to obtain a high degree of 
ozone at the masthead when the air on the upper deck gave 
hardly a trace. At Trincomalee, 1873, during the south- 
west monsoon, the greatest amount of ozone was always 
obtainable at the flag-staff, 175 feet high, next at the top 
of the mainmast of my ship, then on deck, and least in the 
village. The wind, before reaching the deck, got filtered 
through the jungle. The top of the mainmast reached a 
stratum only partially filtered, and the flag-staff towered 
above the tops of the tallest trees. The effects are seen in 
this tabular form: OZONE. 
21 
-s 
0 
3 
CO 
w 
o 
* 
* 
-h 
~ 
o 
•5 
-t- 
0 
o>- 
lb 
o 
► 
<1 
o 
"5 
From 9:30 A. m. to 9:30 p. m.. October. 1873 
TIME OF EXPOSURE. 
14 12 
Oi CO 
The Flag- 
staff, 175 ft. 
high. 
OZONE OBTAINED AT 
Cn <| 
The Maintop, 
120 ft. high. 
Li ti 
On upper 
deck. 
Evaporation would seem to be indicated by the close 
relation which exists between humidity and ozone as a 
source of this latter; but although it contributes towards 
its genesis de longue main, it is not by the act of evapora- 
tion that ozone is produced ; for when evaporation is greatly 
impeded or checked by the elastic force the atmospheric 
vapor has acquired, the ozone may be abundant, and vice 
versa. 
GENESIS OF OZONE. 
But though not a direct factor, evaporation appears essen- 
tial to its formation, for, dormant in the vast quantities of 
vapor which ascend from the surface of the tropical seas at 
or beyond 85° F., it throws into the upper strata prodigious 
quantities of force in the condition of latent heat, which, as 
it becomes liberated by rarefaction and radiation, swells 
out the lower strata and approximates them to the upper; 
while at the same time, if one may judge by the strong 
electricity which accompanies the precipitation of vapor 
without rain on a clear summer’s evening, when a cloudless 
sky permits free radiation, the liberation of heat, the radi- 
ation and condensation in the upper regions similarly affect 
the liberation of electricity, and so augment the electric 
tension of the lower strata that the insulating medium 
(Quetelet) diminished in resisting power by the bulging 
upwards of the strata below it, is no longer able to keep 
the electricities apart,tand in the act of uniting the para- 22 
OZONE. 
magnetic oxygen gets acted upon and condensed into 
ozone. If this supposition be correct, the action of rain, 
etc., is easily understood. Rain would simply act the part 
of a vehicle and bring us ozone from the upper regions, 
and the difference between a smart shower and a drizzle 
would be occasioned by the former coming from a greater 
height, as attested by the greater velocity and momentum 
it acquires in falling in virtue of the accelerating force of 
attraction. It is probably owing to the absence of this 
vehicle that no appreciable increase of ozone is occasioned 
by the noiseless flash-lightning so common in autumn and 
in the tropics. It cannot be doubted that flash-lightning 
is identical in nature with the terrific corruscations, which, 
accompanied by thunder and rain, render the formation of 
ozone appreciable by the olfactories. But there is every 
reason to believe that the former occurs at a much higher 
altitude, at such a distance, in fact, that its accompanying 
sound cannot reach us. By the vehicular function of the 
rain drops the favorable influence which clouds (rain spher- 
ules in a state of flotation) exert, is easily understood. 
OZONE ITS RELATION TO DISEASE, AND ACTION ON THE 
SYSTEM. 
Malignant Cholera.—Scanty ozone, or its total ab- 
sence for a period, was supposed by Steimer and others to 
be the primum mobile of malignant cholera, and Armand 
Isbert looked for its efficient cause in a similar condition of 
ozone combined with the exaltation of temperature, great 
humidity, and stagnation of the atmosphere. During the 
cholera epidemic which swept the East in 1871, and paid a 
visit to H. M. S. “ Magpie,” the ozonic condition presented 
no peculiarity either in point of paucity or abundance; and 
it is not a little remarkable that when the heat reached its 
maximum and brought in its train great humidity and arid 
stagnation, the cholera entirely ceased, but reappeared as 
soon as the great heats were over, and the morning and 
evening atmospheric circulation became again brisk. The 23 
OZONE. 
following table will show the leading features of the two 
cholera periods, and the intervening healthy interval in 
the Persian Gulf in 1871 : 
First Cholera Period, July 1 
to July 20. 
Healthy Interval 
July 20 to Aug.28. 
Second Cholera Period, August28 
to October 1. 
Wind, N. Force, 2 to 6 
Temperature, 75° to 93° 
Vapor tension, 0.654 in 
No Winds 
89° to 104° 
1.106 in 
84 
Variable, 2 to 6. 
80° to 94°. Under double awn’gs. 
1.015 in. 
70. 
2 to 6. 
In both these periods it would be impossible to suppose 
that ozone was in any way connected with the origin or 
prevalence of the disease, and it is quite clear, and was 
recognized by every one on board, that its temporary ces- 
sation was occasioned by the intense heat. 
Consumption has been ascribed by some to a deficiency, 
by others to the opposite extreme, of ozone. Amongst 
those who held the latter was its illustrious discoverer. The 
disease is met with under circumstances unfavorable to the 
presence of ozone, viz., where overcrowding occurs, and 
the ozone not only gets used up, but the atmosphere gets 
vitiated by exhalations from the skin and lungs, and it is 
rather to this hitter pollution that the disease must be as- 
cribed than to ozonic deficiency. In Nassua, N. Provi- 
dence, the sanitarium of the West Indies, the disease com- 
mits the most fearful ravages amongst the negroes, who 
sleep in close, small, windowless huts, stretched out ventre 
a terre, but spares the whites, who sleep in large, well ven- 
tilated apartments. Iu Seychelles it is also met with 
amongst the blacks, who resemble their brethren of the 
West Indies in their domestic arrangements. Amongst the 
Sackalavas, Arabs, and negroes of Madagascar, where the 
ozone is hardly ever above 2 or 4, I never met a single 
case; but their houses are simply constructed of reeds, or 
if of mud, the gables do not reach to the roof, so that free 
ventilation always obtains. In the Indian Islands, where, 
during certain months, an excess of ozone is the rule, and 
in the Falkland Islands, where an excess is constant, con- 24 
OZONE. 
sumption is hardly ever met with—so that I do not believe 
ozone tends, either by exeess or the opposite, to promote 
the disease. But a cure being once established, I believe 
an ozonized atmosphere to be more suitable than one where 
there is but little. 
Sloughing ulcer is common in Mozambique, but so it 
also is in Seychelles, and there it was found to depend on 
the presence of a parasite intermediate in shape between the 
chigoe (jigger) and the cimex lectularious. 
EXCESSS OF OZONE. 
The diseases I have met with most frequently in associa- 
tion with excess of ozone are simple fevers, functional heart 
disorders, and dysentery, but I have never found reason to 
think it had any casual agency in their production. 
INFLUENCE ON THE PROCREATIVE FUNCTIONS. 
The only influence I have been able to obtain satisfactory 
indications of ozone exercising on the human system, is, 
that which it appears to exercise on the procreative func- 
tions ; whether it exalts the vitality of the Grafflan vesicle, 
stimulates the inherent developmental force of the seminal 
corpuscles, increases the activity of the generative organs 
in the male and female equally, I know not; but it certainly 
appears to increase the chances of fecundation, for I have 
found that births are few where ozone is scanty, and nu- 
merous where abundant. In a Sakalava or negro village, 
on the west coast of Madagascar, the most striking features 
are the scarcity of children, and the great number of old 
men and women. The negroes have lost that special apti- 
tude for augmenting the census that characterizes them in 
the Antilles, tand even the neighboring islands Johanna, 
Seychelles and Zanzibar. But the Malagasli negroes breathe 
a scantily ozonized air. On the north side of Cuba and 
Jamaica large families are the rule. On the east coast of 
Central America multiple births are not uncommon. La 
calle de los siele ninos, “ the street of the seven children,” OZONE. 
25 
perpetuates in its name the fecundity of a Santa Martana. 
In July and August, 1867, babies came in platoons along 
the shores of Lake Erie as a result of the high ozonic con- 
dition of the Indian summer months of the year before. 
At Trincomalee, in Ceylon, the most positive evidence of 
this peculiar influence is obtainable; the village is low, but 
little above the sea level, is open to the sea on the north- 
east, and has the jungle to the southwest. From May to 
September the southwest monsoon blows over the island, 
and in passing through the jungle gets robbed of its ozone. 
From October to April the northeast monsoon blows over 
the Bay of Bengal and arrives at the village laden with 
ozone. During April the winds veer from northwest to 
southwest, and ozone is in fair proportion. Here is a suit- 
able field for testing its influence. For this purpose I over- 
hauled the baptismal registers for two years kept by the 
Roman Catholic priests, because their religion requires a 
child to be baptised as soon after birth as possible. Then 
I had access to the public register. Then I examined the 
meterological records kept at the flag-staff, and comparing 
the color slips, showing the ozone on board, found the pro- 
portion of ozone in the village to that of the flag-staff, with 
the result that during the southwest monsoon, viz., from 
May to September, the ozone in the village was 2J ; from 
October to April 8. And the corresponding conceptions 
were 57 and 100, viz., ozone 2.5, conceptions 57 ; ozone 8, 
conceptions 100. 26 
OZONE. 
ATMOSPHERIC OZONE * 
AND THE BEST METHODS FOR ITS OBSERVATION. 
A. W. NICHOLSON, M. D., OF OTISVILLE, MICH. 
Such experiments as I have conducted have principally 
been made with Schoenbein’s test of iodide of potassium 
and starch, that being considered the most reliable test for 
the presence of ozone. 
While the many observations taken by those interested 
in studying the relation of ozone to prevailing disease are 
of great value, it cannot be denied that errors creep in and 
render many single observations of little value. 
Often an apparent decrease in atmospheric ozone will 
exist when an increase will be the actual condition. There 
may be an error by excess of moisture, by an exposure of 
the test-paper to too great velocity of the wind, etc. 
It has been stated that ozone is absent in dwellings. 
While this statement is not incompatible with any theory 
concerning the relations of ozone to conditions of health or 
disease, it is not altogether truthful; for many conditions 
obtain in the in-door atmosphere that occasion error in the 
result of a given observation, and, notwithstanding the 
presence of these conditions, the presence of ozone in 
dwellings has often been discerned by the writer and by 
others. 
It is true that the results of experiments concerning the 
amount of ozone in the air above swamps are often negative, 
yet here there is, without doubt, a source of error in an 
excess of moisture. 
The principal experiments conducted by myself have 
been to determine the presence of ozone in dwellings, and 
the probable influences affecting such tests; to determine 
the relative amount of ozone in pine forests, compared 
State Board of Health Report for 1880, page 285. 27 
OZONE. 
with observations taken in the open country; to ascertain 
the relative amount of' the same element by experiments 
conducted in the smoky atmosphere in proximity to a large 
number of “pits” for the manufacture of charcoal; to 
estimate the amount of ozone existing over swamps; and 
to compare the amount of the same by the exposure of 
tests at the differing elevations of four feet and fourteen 
feet from the ground. Experiments were also made with 
regard to the influence of decomposing animal excreta upon 
the test, compared with tests made one hundred feet distant 
from the first, or from any such element of contamination. 
Observations also were made to determine the effect of 
excess of humidity upon the test; and, lastly, to determine 
the difference in the quantity of active oxygen present in 
the atmosphere of a malarious region with that of an 
atmosphere in a non-malarious region, the same test being 
employed in both localities, and the observations being 
taken at the same hours of the day. 
Many of these observations may be but repetitions of 
those made by other observers, but the information already 
obtained is only sufficient to act as an incentive to other 
investigators to continue their labors in this direction. If 
there is no veritable connection between the varying pro- 
portions of ozone or active oxygen and health or disease, 
inquiry should be continued until the proof of this fact is 
substantiated. If there is a relation, though slight, the 
solution of the problem is worthy of the most untiring 
study. 
In experimenting to determine the proportion in the 
atmosphere of oxidizing elements bearing a relation to 
health and disease, it does not seem necessary to employ a 
test that will verify only the existence of a single factor 
like that of ozone. Oxygen in a state of activity, whether 
generated by electrical or other influences, from oxygen in 
a nascent condition, or from products that easily liberate 
oxygen in a state of activity, like the essential oils, peroxide 
of hydrogen, or resinous compounds, is the desired factor 28 
OZONE. 
to be searched after by the sanitarian and etiologist. If the 
test detects compounds that in themselves produce a colora- 
tion of the test-paper, it appears equivalent to a determin- 
ation of an equal amount of active oxygen. 
Is ozone to be discovered as existing in dwellings ? 
Max Von Pettenkofer, of Munich, in an article in the 
Contemporary Review, entitled, “The Hygienic Influence 
of Plants,” makes the following assertion in regard to the 
relation of ozone to the appearance or disappearance of dis- 
ease ; “ But one fact which was observed from the first, 
shows that it cannot be so; for the presence of ozone can 
never be detected in our dwellings, not even in the cleanest 
and best ventilated. Now, as it is a fact that we spend the 
greater part of our lives in our houses, and are better than 
if we lived in the open air, the hygienic value of ozone 
does not seem so very great.” 
Such a declaration, proceeding from such an influential 
origin, would, if erroneous, lead to many false deductions. 
That it is incorrect, the succeeding exhibit of the results of 
observations taken by myself, appears to prove. The ob- 
servations were made with Schcenbein’s test, moistened 
before exposure. The apartment where the experiments 
were made was well constructed, and a free circulation from 
the external air permitted, when there was the greatest 
coloration, allowing motion to the air and access of moisture. 
Where least coloration occurred every avenue to the external 
air was closed as much as possible. 29 
OZONE. 
Date. 
Internal, 
Observation. 
External 
Observations. 
Remarks. 
1880. 
Night. 
Day. 
Night. 
Day. 
1 
3.5 
All numbers cor- 
“ 11 
0 
1 
2 
3 
respond to scale of 
“ 12 
1 
2 
2.5 
3 
10 degrees of color- 
“ 13 
2 
2.5 
3.5 
3 
ation. 
“ 14 
1 
1 
3.5 
3 
Strong wind. 
Average. 
1 
1.5 
2.9 
3.1 
EXHIBIT A. 
During the winter, in a north room of my own dwelling, 
where an effort was made to exclude the factor of ventila- 
tion, a coloration of three degrees was obtained. The tem- 
perature of the room was fifteen degrees Fahr., and a strong 
wind was blowing from the north. Externally a coloration 
of nine degrees was obtained. At the same time, in an- 
other north room of the same house, where the tempera- 
ture amounted to seventy degrees Fahr., a distinct trace 
was discernible. At another time, when the external air 
was quiet, there was obtained one degree of coloration in 
the first room, where the temperature was forty-five de- 
grees Fahr., and in the second room no coloration, with a 
temperature of seventy degrees Fahr. These results would 
suggest that a certain amount of motion of the air exceed- 
ing that usually existing in dwellings, would be auxiliary 
to conditions producing a manifestation of the presence of 
ozone therein. That the excess of moisture externally over 
that in the interior of dwellings is not a factor to be con- 
sidered, seems proved by experiments made by the writer 
in regard to effects of moisture on the test as existing in 
dwellings. It was found that in rooms ventilated, when 
the external air was not disturbed by the influence of 
storms, the amount of moisture (absolute humidity) inter- 
nally was equal to the amount of moisture externally, and 30 
OZONE. 
that there was sometimes an excess of moisture in the in- 
terior of a dwelling over that exterior, when the amount 
of ozone was slight or entirely absent in the dwelling. 
It is probable that sunshine is a condition aiding the pro- 
duction of ozone in dwellings, as more ozone was present 
during the day than night. 
Prof. R. C. Kedzie says: “Ozone is doubtless formed 
in every sunlit room, and by its formation and destruction 
a vast amount of materies morbi may be destroyed, and it is 
no satisfactory proof that it is of no worth or influence be- 
cause no residual ozone remains to act upon our test-paper.” 
Just what the influence upon the test is that is produced 
by the presence of carbon compounds, it is difficult to ex- 
press. That its presence may modify the results of an ex- 
periment to ascertain the amount of ozone present is pos- 
sible. To determine if the presence of pure carbonic acid 
would decolorize a slip of test-paper, already colored by 
exposure, I subjected a moistened slip to an atmosphere of 
carbonic acid by collecting the same over a pneumatic 
trough. On the gas being washed by passage through 
water the color upon the slip remained unaltered. On sub- 
jecting it to the influence of the gas as it escaped unwashed 
from the generator, a decolorization immediately occurred. 
This was found to be due to the presence of sulphurous 
acid. 
Smoke is an element that will decolorize a slip of the 
test-paper already charged with liberated iodine. It is 
probable that the volume of smoke that usually, though 
imperceptibly, escapes from the stove, contains some prop- 
erty, perhaps that of sulphurous acid, that causes a change 
in the iodine as rapidly as it is liberated, resulting in the 
formation of a colorless iodate. To demonstrate the effect 
of gases, or smoke, generated by the stove, I introduced a 
glass tube through an opening of the stove into the midst 
of burning coals, and into the outer extremity of the tube 
I placed some of the test-paper already colored by the action 31 
OZONE. 
of ozone. The result was a marked loss of the color on the 
paper. That this was not due to the action of increased 
temperature was proved by exposing a similar paper to the 
action of the same temperature at other points. 
Although it is apparent that the amount of ozone in 
dwellings is act ually less than that in the external air, it is 
also true that there exist agents that at present prevent an 
accurate estimate from being obtained by Schcenbein’s test. 
That active oxygen bears to organic life—to physiological 
and pathological conditions—some essential relation, is a 
proposition yet open for discussion. To declare that its 
presence in dwellings is not proved is apparently an error. 
Even were it absent from dwellings, that circumstance 
could not prove its non-relation to health or disease. With- 
out endeavoring to court discussion upon this important 
subject, it seems plausible to the writer that no oxygen 
enters the blood in any other state than as active oxygen. 
It may be that the large area of the alkaline pulmonary 
secreting surface, subject to the results of continuous evap- 
oration, is in a condition to effect a generation of sufficient 
active oxygen to supply the blood with that which it re- 
quires. The excess in the external atmosphere may be of 
importance to the individual when a decrease in the exter- 
nal temperature intuitively directs him to take less deep 
inspirations than the warmer and drier atmosphere of the 
dwelling demanded, thus rendering the labor of the lungs 
less in supplying a given quantity of oxygen to the blood. 
If it should be objected that the ratio of active oxygen 
necessary to sustain the physiological requirements of the 
blood is not constant, I would inquire if the ratios of most 
meteorological conditions are constant. 
During portions of the months of March and April, 
1878, while the ground was frozen, and part of the time 
overspread with snow, I secured a record of observations 
of the amount of ozone in a small pine forest, about eight 
miles distant from my usual point of observation. The 32 
OZONE. 
following exhibit represents the comparative amount ex- 
isting at both places at the same time: 
EXHIBIT B. 
Date. 
1878. 
Pine 
Forest. 
Open 
Country. 
DATE, 
1878. 
Pine 
Forest. 
Open 
Country. 
Night 
Day. 
Night 
Day. 
Night 
Day. 
Night 
Day. 
6 
5 
8 
4 
4 
5 
5 
3 
“ 5 
6 
5 
6 
4 
“ 
21 
5 
4 
4 
4 
“ 6 
6 
5 
4 
5 
“ 
22 
5 
4 
8 
5 
“ 7 
6 
5 
10 
8 
** 
23 
5 
5 
5 
5 
“ 8 
4 
4 
8 
7 
*• 
24 
4 
6 
4 
6 
“ 9 
5 
4 
5 
4 
«• 
25 
5 
5 
5 
5 
“ 10 
5 
5 
8 
4 
•* 
26 
5 
5 
5 
5 
•* 11 
5 
5 
6 
8 
»* 
27 
4 
4 
8 
5 
•• 12 
5 
5 
10 
9 
28 
4 
4 
9 
8 
“ 13 
6 
5 
10 
9 
29 
4 
5 
8 
4 
“ 14 
4 
5 
8 
9 
»* 
30 
5 
5 
4 
4 
. “ 15* 
2 
4 
1 
4 
» l 
31 
5 
5 
9 
8 
“ 16 
5 
5 
10 
8 
April 
1 
5 
5 
7 
“ 17 
5 
5 
9 
10 
2 
4 
5 
3 
“ 18 
4 
9 
8 
3 
4 
3 
4 
3 
8 
Average 
4.80 
4.70 
6.93 
5.90 
*Frost on night ozonoscope. 
Note.—Night observations, from 9f. m. to 7 a. m,; 
day observations, from 7 
a. m. to 2 P. M. 
It is generally believed that ozone, or that product nearly 
identical in its nature, the peroxide of hydrogen, exists in 
excess amidst coniferous vegetation over that found in most 
other regions, but the above exhibit presents results con- 
trary to that which ought to be expected to exist. This 
difference is, no doubt, in a great degree due to the time 
of year being when there was the least development of 
vegetable products, to the more confined circulation of the 
air, and perhaps to excess of humidity. The ground was 
low. 
During the preceding summer, in the months of August 
and September, I secured the results of observations taken 
in the same pine forest, as represented in the following ex- 
hibit : OZONE. 
33 
EXHIBIT C. 
Date. 
1877. 
Pine 
Forest. 
Open 
Country. 
Date. 
1877. 
Pine 
Forest. 
Open 
Country. 
Night 
Day. 
Night 
Day. 
Night 
Day. 
Night! Day. 
3 
4 
1 
4 
Sept 
11 
0 
1 
1 
2 
27 
4 
3 
3 
4 
12 
2 
3 
3 
3 
" 28 
0 
1 
0 
1 
13 
0 
3 
0 
2 
“ 29 
3 
4 
2 
3 
14 
0 
4 
0 
3 
“ 30 
1 
3 
1 
2 
15 
3 
3 
2 
3 
“ 31 
4 
2 
3 
4 
1 4 
16 
2 
3 
2 
3 
4 
4 
4 
» 3 
• 4 
17 
4 
4 
3 
4 
“ 2 
1 
4 
3 
4 4 
18 
3 
4 
1 
4 
“ 3 
3 
3 
3 
4 
19 
3 
4 
2 
4 
“ 4 
3 
4 
3 
4 
20 
1 
3 
1 
2 
“ 5 
2 
3 
2 
3 
21 
1 
4 
1 
3 
“ 6 
3 
3 
3 
4 
22 
2 
3 
0 
3 
“ 7 
1 
4 
1 
4 
23 
3 
4 
1 
3 
“ 8 
1 
3 
1 
3 
4 4 
24 
3 
2 
3 
3 
“ 9 
1 
4 
1 
4 
H 
25 
1 
2 
2 
3 
1 10 
1 
3 
3 
Average 
2.09 
3.13 
1.80 
2.16 
In the above exhibit we find a considerable difference in 
the two averages of night ozone, that found in the pine 
forest being in excess. The variation in the amount of ozone 
ascertainable during the day was slight. Were a sanitarium 
to be established in the vicinity of a pine forest for the 
sake of the salubrity of its immediate atmosphere it would 
appear expedient to consider other elements liable to affect 
the health, than ozone alone. 
Date. 
1877. 
Coal 
Pits. 
Open 
Country. 
Date. 
1877. 
Coal 
Pits. 
Open 
Country. 
Night 
Day. 
Night 
Day. 
Night 
Day. 
Night 
Day. 
2 
3 
2 
4 
Aug. 12 
2 
3 
3 
4 
“ 2 
1 
2 
1 
2 
“ 13 
2 
3 
3 
4 
“ 3 
1 
3 
1 
4 
“ 14 
1 
3 
3 
4 
“ 4 ::::::::: 
1 
2 
0 
3 
“ 15 
1 
3 
2 
4 
*• 5 
1 
3 
1 
4 
“ 16 
1 
5 
1 
2 
“ 6 
2 
4 
4 
4 
“ 17 
2 
3 
1 
3 
“ 7 
1 
3 
2 
3 
“ 18 
1 
3 
0 
4 
“ 8 
1 
4 
3 
3 
“ 19 
1 
2 
1 
4 
“ 9 
1 
4 
2 
4 
20 
2 
2 
1 
4 
“ 10 
2 
3 
3 
4 
“ 21 
1 
2 
2 
4 
“ 11 
1 
4 
0 
3 
Average 
1.33 
3.00 
2.71 
3.57 
EXHIBIT D. 
Exhibit D records the results of observations taken in 
the borders of a pine forest, but in close proximity to coal- 
pits, as compared with those taken at a distance and free 
from any known cause of local disturbance to the test. 34 
OZONE. 
The heavy night air at the pits was surcharged with smoke 
that during the daytime was less concentrated. The results 
of the observations at this point were, at night, almost 
negative, although recorded as one degree of coloration 
whenever a trace was discernible. The negative results 
obtained here are accounted for by the presence of the de- 
colorizing carbonaceous elements of the atmosphere asso- 
ciated with the element of excess of humidity. It does not 
seem unreasonable to conclude that the quantity of ozone 
present in an atmosphere subjected to the above mentioned 
influences, cannot be determined by the employment of 
Schoenbein’s test. 
During the construction of these coal-pits, in the year 
preceding these experiments, the amount of sickness at, and 
near to, them was very great. In a population amounting 
to one hundred and fifty, nearly one-fourth were simulta- 
neously afflicted with fevers of a periodic type. Clay and 
porous soils were being overturned for the first time, and 
large belts of timber were being felled, opening avenues 
for swamps and ponds. The greatest prevalence of sick- 
ness was during the burning of some of the pits first con- 
structed. The season during which the observations were 
taken was marked by a diminution in the number of cases 
of fever. 
Another month’s observations taken at the same place 
gave results almost identical to those above given. 
The following exhibit represents the comparative amount 
of ozone existing over a swamp two miles from the point 
where the observations were taken with wdiich they are 
compared. They were also taken simultaneously with those 
observations relating to the quantity of ozone existing in a 
pine forest. OZONE. 
35 
EXHIBIT E. 
Date. 
1877, 
Over Swamp. 
Point free 
FROM SUCH 
Influences. 
Date, 
1877. 
Over Swamp. 
Point free 
FROM SUCH 
Influences, 
Night. 
Day, 
Night. 
Day. 
Night. 
Day. 
Night. 
Day, 
Aug. 26 
1 
2 
1 
4 
Sep, 
10 
0 
0 
3 
3 
** 27 
1 
2 
3 
4 
44 
11 
0 
1 
1 
2 
“ 28 
1 
1 
0 
1 
*{ 
12 
0 
3 
3 
3 
“ 29 
1 
3 
2 
3 
i * 
13 
0 
1 
0 
2 
“ 30 
1 
1 
1 
2 
14 
0 
2 
0 
3 
“ 31 
4 
5 
3 
4 
15 
2 
2 
2 
3 
Sept, 1 
0 
1 
4 
3 
16 
1 
2 
2 
3 
“ 2 
0 
0 
3 
3 
17 
0 
3 
3 
4 
“ 3 
0 
1 
3 
4 
18 
0 
1 
1 
4 
“ 4 
0 
3 
3 
4 
19 
2 
4 
“ 5 
0 
1 
2 
3 
*< 
20 
0 
5 
1 
2 
“ 6 
0 
1 
3 
4 
• I 
21 
0 
4 
1 
3 
“ 7 
0 
1 
1 
4 
ft 
22 
0 
0 
0 
3 
“ 8 
0 
3 
1 
3 
“ 9 
0 
5 
1 
4 
Av’ge, 
0,44 
1.92 
1.78 
3.17 
In the above exhibit a great difference is seen to exist be- 
tween the averages of the two points of observation. 
Whether this difference is due to the emission of gases 
destructive to a large portion of the atmospheric ozone nat- 
urally present, or whether the same interferes with a depo- 
sition of liberated iodine, or whether the apparent absence 
is due to an excess of moisture sufficient to decolorize the 
paper, are inquiries that can only be determined by exper- 
imentation. The excess of humidity naturally present at 
such a point appears to offer some explanation. 
The experiments over the swamps were made by sus- 
pending slips of test-paper about three feet above the soil. 
They were exposed to a free circulation of the air, but pro- 
tected from the sunlight. During the time these observa- 
tions were being taken the several families residing near 
this swamp suffered more or less from frequent attacks of 
periodic fever. 
With a view to ascertain the comparative results of ob- 
servations for the presence of ozone as it existed at two 
differing points of elevation, fifty-four observations were 
conducted at the elevations of four and fourteen feet from 
the ground. « 
The following exhibit contains the results of these obser- 
vations : 36 
OZONE. 
EXHIBIT F. 
Higher 
Elevation. 
Lower 
Elevation. 
Remarks. 
Night 
Day. 
Night | 
Day. 
4 
9 
7 
9 
Rain all day. 
8 
8 
9 
7 
Rain all day. 
7 
7 
8 
8 
Rain all day. 
9 
5 
8 
5 
Rain in night. 
4 
4 
8 
6 
Rain in morning. 
7 
5 
8 
5 
Rain all day. 
4 
5 
5 
6 
Fair. 
5 
5 
6 
5 
Fair. 
4 
3.5 
4 
3.5 
Fair. 
4 
3.5 
3 
3.5 
Rain in night, paper lost color. 
1 
4 
2 
4 
Fair. 
2 
3 
2 
3 
Fair. 
3.5 
3.5 
1 
4 
3.5 
4 
Fair. 
Average. 
4.53 
5.07 
5.50 
5.30 
These observations do not demonstrate that actually a 
greater quantity of ozone was present in the lower stratum 
of the air than in the upper. The variation of the degree 
of moisture at the two points may lead to an explanation ; 
yet the excess of ozone at the lower plane seemed to cor- 
respond with the presence of aqueous precipitation and a 
consequent pulverization of the rain-drops. This might 
have led to the generation of ozone by increase of electri- 
cal influences, as spoken of by Fox in his work on “ ozone.” 
At the suggestion of Dr. Baker, I directed my attention 
to the relative quantity of ozone existing near decomposing 
animal excreta as compared with that found one hundred 
feet distant from any such contaminating influence. OZONE. 
37 
EXHIBIT G. 
Date, 
1879. 
Impure Air. 
Pure Air. 
Night. 
Day. 
Night. 
Day. 
June 9 
2.5 
3.5 
4.5 
3.5 
“ 10 
2 
2.5 
3.5 
3.5 
“ 11 
1 
3 
2 
3 
“ 12 
2 
2.5 
2.5 
3 
“ 13 
3 
3.5 
“ 14 
3 
3 
3.5 
3 
Average 
2.3 
2.9 
3.3 
3.2 
Both ozonoscopes were suspended at a distance of six feet 
from the ground, and both were subjected to the influence 
of the same degree of atmospheric humidity. It is there- 
fore probable that the variation in the degree of coloration 
was due to the exposure of one ozonoscope to the influences 
of rapidly oxidizing effete material. 
In considering the influences existing that might have 
occasioned an errf»r in the results of the observations re- 
corded in the foregoing exhibits, none is more apparent 
than that of excess of moisture. Some atmospheric condi- 
tions associated with twenty observations where there was 
a total absence of coloration are shown in the succeeding 
exhibit: 38 
OZONE. 
EXHIBIT H. 
Number of 
Case. 
Lowest 
Tempera- 
ture. 
Velocity 
of Wind— 
Miles per 
Hour. 
Relative 
Humidity 
Remarks. 
1 
44 
2 
75 
Few clouds. 
2 
37 
2 
96.6 
Cloudy. Frost on test-paper. 
3 
34 
2 
96.6 
Frost. 
4. 
32 
2 
96.6 
Slightly cloudy. 
5 
32 
2 
96.6 
Slightly cloudy. 
6 
32 
2 
96.6 
Slightly cloudy. 
7 
32 
2 
96.6 
Slightly cloudy. 
8 
25 
2 
100 
Slightly cloudy. 
9 
41 
2 
96.6 
Slightly cloudy. 
10 
45 
12 
100 
75 per cent, of clouds. Heavy dew. 
11 
44 
2 
100 
Heavy dew. 
12 
57 
2 
100 
Smoky,—75 per cent, of clouds. 
13 
44 
2 
85 
Heavy dew. 
14 
44 
2 
100 
Heavy dew. No clouds. 
15 
44 
2 
100 
Heavy dew. 
16 
59 
2 
100 
Heavy fog,—50 per cent, clouds. 
17 
46 
2 
96.6 
Heavy fog,—75 per cent, clouds. 
18 
49 
2 
96.6 
Heavy dew. No clouds. 
19 
25 
2 
100 
Frost. No clouds. 
20 
57 
2 
96.6 
90 per cent, clouds. 
The above cases represent nearly all those of complete 
obliteration of color occurring during a period of three 
years. These all occurred during the night observation. 
With each case there was nearly, or quite, a complete satu- 
ration of the atmosphere with moisture. 
In one hundred and forty-three observations taken by 
myself to determine the relative value of Schoenbein’s test 
when exposed to the air dry, and when exposed after having 
been previously moistened, I discovered an excess of color- 
ation in the dry slip over that of the wet slip forty times, 
the largest excess being five degrees of coloration. During 
these forty instances the sky was covered with one hundred 
per cent, of clouds. In only six instances in the whole 
number of observations was the wet slip colored in excess 
of the dry when there was one hundred per cent, of clouds. 
When there was less than seventy-five per cent, of clouds 
the moistened slip was more greatly colored than the dry. 
While I at one time thought it possible that some electrical OZONE. 
39 
phenomena might be a cause of the ozonoscopic conditions 
just mentioned, I am now disposed to believe the cause to 
bear relation more to hygrometric states influenced by the 
varying per cent, of clouds. A dry slip is exposed to the 
influences of these conditions, and a gradual deposition of 
the moisture upon the same aids rather than retards the 
coloration. But when a moistened slip is exposed to the 
influences of these conditions of the atmosphere it is liable 
to become blanched as fast as the iodine is deposited. Cor- 
nelius B. Fox says: “If the iodine of starch be so slightly 
soluble in water, how does it happen that these tests often 
and rapidly become, when they are wet, completely blanched ? 
If a deeply tinted Negretti’s test be cut into small portions 
and placed in a little distilled water, some difficulty will be 
experienced in rendering the fragments colorless. Many 
hours, and perhaps a day or two will elapse before all color 
is removed from them. If, on the other hand, a colored 
Negietti’s test be kept in a moist condition with distilled 
water, conducted to it by a fine thread of lamp-wick or 
darning-cotton, the color will rapidly disappear. In the 
latter experiment the iodide of starch becomes vaporized 
from the test.” 
It is thus proved that in more than one-fourth of the 
cases where observations are taken writh Schcenbein’s test, 
providing the same proportion of days all cloudy existed 
as above illustrated, the dry slip will exhibit the greatest 
coloration, and in the remaining cases the deepest tint 
would be exhibited by means of the wet slip. 
Through the kindness of a friend residing in Litchfield 
county, of the State of Connecticut, I was enabled to secure 
results of ozonometric observations among its non-malarious 
hills, during the summer of the year 1878. The record of 
these observations is presented in the following exhibit in 
comparison with the record of observations taken at this 
point, where periodic fevers prevail: 40 
OZONE. 
EXHIBIT I. 
Date, 
1878. 
Litchfield 
County, 
State of 
Connecticut. 
Otisville, 
Michigan. 
Date, 
1878. 
Litchfield 
County, 
State of 
Connecticut. 
Otisville, 
Michigan. 
Night. 
Day. 
Night. 
Day. 
Night. 
Day. 
Night. 
Day. 
Aug. 
6 
4 
5 
3 
3 
Sept. 9 
0 
2 
4 
2 
7 
4 
4 
3 
3 
“ 10 
0 
3 
2 
3 
8 
3 
3 
3 
4 
“ 11 
0 
4 
2 
2 
9 
4 
6 
3 
4 
“ 12 
2 
3 
3 
10 
4 
4 
3 
4 
“ 13 
1 
3 
4 
4 
11 
3 
4 
1 
1 
- 14 
0 
2 
4 
1 
12 
3 
4 
* 0 
s 
“ 15 
2 
3 
1 
2 
13 
1 
3 
3 
3 
“ 16 
0 
2 
5 
3 
14 
0 
2 
4 
3 
“ 17 
0 
3 
2 
3 
15 
0 
3 
4 
3 
“ 18 
0 
3 
3 
3 
16 
2 
3 
4 
3 
“ 19 
3 
3 
17 
2 
3 
1 
3 
“ 20 
2 
2 
3 
4 
18 
2 
4 
1 
3 
“ 21 
1 
2 
3 
3 
27 
0 
3 
t o 
3 
“ 22 
2 
3 
1 
3 
28 
1 
3 
3 
3 
“ 23 
0 
2 
3 
2 
29 
1 
3 
4 
4 
“ 24 
0 
2 
3 
4 
30 
1 
2 
1 
4 
“ 25 
2 
3 
3 
3 
31 
0 
3 
3 
4 
“ 26 
1 
2 
4 
3 
Sept. 
1 
3 
2 
3 
2 
“ 27 
3 
2 
§ 1 
2 
2 
0 
2 
4 
3 
“ 28 
1 
3 
3 
3 
3 
0 
3 
4 
4 
“ 29 
0 
3 
4 
2 
4 
2 
1 
3 
3 
“ 30 
0 
2 
4 
2 
5 
4 
1 
t 0 
3 
Oct 1 
0 
2 
3 
1 
6 
2 
3 
t 0 
3 
“ 2 
2 
3 
4 
3 
7 
0 
2 
4 
4 
3 
3 
3 
3 
2 
8 
1 
3 
4 
2 
— 
— 
Avr’ge. 
1.38 
2.82 
2.77 
2.90 
* Heavy dew in morning. 
t Fog in morning. 
T Great amount of moisture in night. 1 Frost in morning- 
The small quantity of ozone exhibited for the night in 
the record obtained from Connecticut impresses one with 
the belief that some atmospheric conditions existed that 
failed to testify to the actual amount of ozone present. 
Excessive moisture appears to have been one of these con- 
ditions, as reported by the observer to me. 
As local conditions greatly affect the test for ozone, the 
observations that might be taken in other parts of this 
mountainous country might present results more in unison 
with the popular belief that active oxygen exists in greatest 
quantities amidst the mountains. 
As spoken of, the velocity of the wind, if it is great, and 
the air is saturated with moisture, will occasion a decolori- 
zation of the test-paper unless protected from its influence. 
But if a test-paper be exposed to the free action of the OZONE. 
41 
wind when the air is not saturated with moisture a greater 
coloration will often occur Than when 'protected from the 
action of the wind. 
COLORATION OF BOTH SIDES OF THE TEST-PAPER. 
Although Schoenbein’s test is considered the most reliable 
in use for the detection of ozone, something yet remains to 
be done in order to render even this test perfect, exclusive 
of the effects of such conditions as already have been men- 
tioned. 
In the manufacture of the test-paper I use, only one side 
of it is covered with the preparation that by chemical alter- 
ration and change of color enables us to estimate the rela- 
tive amount of ozone present. In this connection Dr. H. 
B. Baker remarks that “ Some test- paper prepared in Ger- 
many, examined by me, seemed to be like Swedish filter- 
paper ; it was of loose texture, and on exposure was soon 
colored on both sides alike, but the degree of coloration 
was more uniform under varying conditions than it is on 
the paper used by the observers in Michigan. The loose 
texture paper seemed to be exceedingly prone to take on a 
color equaling from 2 to 4 on our scale, but did not seem to 
be as ready to show shades above or below those. On 
comparing it with our paper, it was found to fade quicker 
after being moistened, and I came to believe that it was 
not so accurate as is ours for the purpose of indicating the 
relative qualities of ozone in the atmosphere.” In exam- 
ining the test-paper, after exposure, I have frequently 
found that the side of the paper upon which there was none 
of the preparation, exhibited the greater coloration. To 
determine, if possible, the cause of this, I recorded in a 
series of observations, as shown in the following exhibit, 
the degrees of coloration that appeared upon both sides of 
the paper. In the first series the number of observations 
was 34. In 19 of these observations there was the deeper 
coloration on the side not having the preparation on it. 
The same degree of coloration occurred upon both sides at 42 
OZONE. 
once in 13 instances. There was a deeper coloration on 
the side containing the compound of starch and iodide of 
potassium, twice: 
EXHIBIT K. 
First Series of Observations on the Influence of Relative Humidity 
upon the Coloration by Ozone of Both Sides of the Test-paper. 
Coloration, Marked 
on a Scale of 10°. 
Relative Humidity.—Per Cent, of Satura- 
tion of the Air at the Beginning of the 
Exposure when the Coloration was as 
Specified. 
On Front 
of Test- 
paper. 
In Back of 
Test-Paper 
All. Obser- 
vations in 
the Series. 
Greatest 
Color on 
Front of 
Paper. 
Same Color 
on Both 
Sides. 
Greatest 
Color on 
Back of 
Paper. 
2 
2 
82.3 
82.3 
1 
2 
95.3 
95.3 
2.5 
3 
95.3 
95.3 
2 
3 
76.0 
76.0 
2 
3.5 
84.2 
84.2 
2.5 
3.5 
76.0 
76.0 
2.5 
3.5 
74.9 
74.9 
2 5 
3 5 
87.1 
87.1 
1 
2 
100.0 
100.0 
35 
3 
89.3 
89.3 
1.5 
2.5 
81.4 
81.4 
3.5 
3 5 
100.0 
100.0 
3 
3 
100.0 
100.0 
2 
3 5 
76.9 
76.9 
2.5 
2 
100.0 
ioo.o 
3.5 
3.5 
100.0 
ioo.o 
2 
3 
53.7 
53.7 
2.5 ’ 
3.5 
87.1 
87.1 
2 
2 
93.2 
93.2 
3 
3 5 
86.4 
86.4 
3 
4 
85.8 
85.8 
2.5 
92.6 
92.6 
3 
3 
92.8 
92.8 
2.5 
3.5 
86.6 
86.6 
2.5 
3.5 
93.1 
93.1 
3 
3 5 
71.0 
71.0 
3.5 
3 5 
100.0 
100.0 
3 
3 
94.4 
94.4 
3 
3 
100.0 
100.0 
2.5 
2.5 
95.0 
95.0 
3 
3.5 
85.8 
85.8 
3 
3 
80.5 
80.5 
1.5 
2 5 
69.4 
69.4 
2.5 
2.5 
100.0 
100.0 
Total.... 
85.5 
102.5 
2986.1 
189.3 
1230.8 
1566.0 
Av’rages 
2.51 
3.01 
87.8 
94.7 
94.7 
82.4 OZONE. 
43 
Assistant Professor F. S. Kedzie, of the Agricultural 
College, at Lansing, Mich., suggests that these conditions 
may appear from the existence of a thin film, or tough pel- 
licle, sometimes formed over the starch compound, thus 
preventing the access and ready action of ozone in setting 
free the iodine; the degree of coloration varying according 
to the condition of the surface of the test-paper, and ac- 
cording to certain conditions of atmospheric humidity ex- 
isting at the time of the exposure of the test. 
It is probably true that varying conditions of moisture 
have a marked influence with other influences producing 
the results referred to. 
In sixteen of the nineteen instances where there was a 
deeper tint on the back of the paper the relative humidity 
was less than ninety per cent., ranging from fifty-three per 
cent, upwards. In three instances where there was the 
deeper tint upon the back the relative humidity exceeded 
ninety per cent. In only one instance did the relative 
humidity mount to one hundred per cent. In only three 
instances out of the fifteen when the front had a coloration 
equal to that upon the back of the test-paper, or a greater 
coloration, the relative humidity was less than ninety per 
cent. In twelve instances when the coloration upon the 
front was equal to, or greater than that upon the back, the 
relative humidity exceeded ninety per cent. In seven of 
the fifteen instances when the degree of coloration on the 
front was equal to, or greater than, that upon the back, the 
relative humidity was one hundred per cent. This would 
seem to prove that conditions of moisture have a decided 
influence in affecting the phenomena in question. 
After an exposure of the test-paper for a time sufficient 
to produce a coloration, if there is a deeper tint upon the 
back than on the front side a removal of a thin portion of 
the starch from the front will not disclose as deep a tint as 
there is upon the back, nor will as marked a coloration 44 
OZONE. 
appear in front until all the starch is removed, when both 
sides of the paper exhibit the same degree of discoloration. 
The paper which is used in preparing the test readily 
absorbs a portion of the solution of iodide of potassium 
contained in the starch compound, and on exposure to 
oxidizing elements exhibits chemical change as well as the 
prepared starch. The difference in the texture of the paper 
itself from the texture of the starch compound would sug- 
gest the existence, in the paper and compound, of differing 
qualities for the absorption of moisture. 
An average degree of moisture seems to be a condition 
rendering the paper saturated with a solution of iodide of 
potassium in starch-water a more delicate test than the 
starch and iodide ol potassium test. Where excess of 
moisture obtains, the starch and iodide of potassium test 
appears to be the most reliable. 
The preceding exhibit does not contain an extensive 
series of observations as we would wish to have in order to 
establish conclusive evidence, but was all we had at the 
time of writing the foregoing. Since that time additional 
observations have been made, and the results are shown in 
the following exhibit: OZONE. 
45 
EXHIBIT L. 
Second Series of Observations on the Influence of Relative Humid- 
ity upon the Coloration by Ozone of Both Sides of the Test-paper. 
Coloration, Marked 
on a Scale of 10°. 
Relative Humidity—Per Cent, of Satura- 
tion of the Air at the Beginning of the 
Exposure when the Coloration was as 
Specified. 
On Front of 
Test-paper. 
On Back of 
Test-paper. 
All Obser- 
vations in 
the Series. 
Greatest 
Color on 
Front of 
Paper. 
Same Color 
on Both 
Sides. 
Greatest 
Color on 
Back of 
Paper. 
3.5 
3.0 
100.0 
100.0 
3.0 
3.5 
3.5 
85.8 
85.8 
4.5 
75.5 
75.5 
2.5 
1.5 
4.0 
3.5 
3.0 
86.2 
86.2 
3.0 
4.0 
3.0 
83.4 
83.4 
100.0 
100.0 
100.0 
loo.o 
5.0 
4.0 
91.3 
91.3 
3.5 
2.5 
85.8 
85.8 
2.0 
3.0 
74.5 
74.5 
2.0 
3.0 
3.5 
75.9 
75.9 
3.0 
84.0 
84.0 
3.0 
3.0 
91.4 
91.4 
3.5 
4.0 
83.4 
83.4 
3.0 
2.5 
83.4 
83.4 
7.0 
3.0 
93.1 
93.1 
3.0 
2.0 
100.0 
100.0 
8.0 
3.0 
91.4 
91.4 
3.0 
2.5 
91.6 
91.6 
4.0 
2.5 
100.0 
100.0 
3.0 
2.5 
100.0 
100.0 
3.0 
3.0 
90.6 
90.6 
2.5 
4.0 
100.0 
100.0 
3-5 
3.5 
100.0 
100.0 
4.0 
4.5 
79.3 
79.3 
2J> 
2.5 
92.6 
92.6 
2.5 
3.0 
84.0 
84.0 
3.0 
3.0 
100.0 
100.0 
4.0 
3.0 
92.6 
92.6 
2.0 
3.0 
79.3 
79 3 
2.5 
3.0 
69.6 
96.6 
3.5 
2.5 
932 
93.2 
3.0 
3.0 
100.0 
100.0 
4.0 
3.5 
92.6 
92.6 
3.5 
3.5 
100.0 
100.0 
8.0 
6.0 
100.0 
100.0 
6.0 
5.0 
90.5 
90.5 
3.5 
2.5 
100 0 
100.0 
3.0 
4.0 
83.4 
83.4 
Totals... 
139.5 
128.5 
3524.8 
1605.5 
933.1 
986.2 
Average 
Av. of 
both ser. 
3.58 
3.29 
90.4 
94.4 
93.3 
82.2 
3.08 
3.16 
89.2 
94.5 
94.1 
83.2 46 
OZONE. 
In the foregoing exhibit the statement of the relative 
humidity is made for the time when the test-paper -was put 
out for exposure. In nearly all the cases where there was 
less coloration on the back of the paper than on the front, 
and a relative humidity of less than ninety per cent, at the 
time the test-paper was put out, the relative humidity was 
over ninety per cent, when the paper was compared with 
the scale, showing that there was an increase of moisture 
after the paper was first exposed. 
When the back of the paper was the most deeply colored, 
and on its first exposure the relative humidity was more 
than ninety per cent, (another exception to the general 
rule), there was almost always a considerable decrease in 
the relative humidity. 
SUGGESTIONS FOR IMPROVED METHODS OF OBSERVATIONS. 
Negative results obtained by the exposure of Schoenbein’s 
test-paper in dwellings seem to be due as much to elements 
affecting the liberated iodine as to absence of ozone. This 
test, then, seems to be of little use in determining the 
presence of ozone in dwellings. 
Valuable as are the general results of ozonometric obser- 
vations, it is obvious that many of them are clouded with 
error. How to remove these errors is a subject important 
to all those interested in the study of ozonometry as to its 
meteorological, physiological, or pathological relations. 
Much study is yet necessary before the best methods for 
accurately estimating the quantity of ozone present at any 
time in the atmosphere will be determined. In the use of 
Schoenbein’s test, in order to obtain the maximum results of 
an observation where it is necessary to guard against excess 
of moisture, the exposure of a dry and wet slip at the same 
time, would appear to be a proper method to adopt; also to 
suspend them at such points as where the condensation of 
vapor would be least liable to occur. To make the period 
of time less for the exposure of test-paper would be another 
means to obtain maximum results of an observation. OZONE. 
47 
It is well known that by increased velocity of the wind 
more ozone may be carried to a given point than there 
would be if the velocity were less. To determine the quantity 
of ozone, therefore, liable to affect the health of an individual 
subjected to the influence of rapid currents of air, it is 
desirable to expose the test-paper to the same current. But 
the loss of the liberated iodine as a result of such exposure, 
suggests that in order to obtain the deepest coloration the 
slip must be protected from too great velocity of the wind, 
especially when there is an excess of moisture in the 
atmosphere.