NATURAL LAW 
APPLIED TO 
ETIOLOGY 
E. R. EGGLESTON, M. I).. Mt. Yernoi\oinW_ 
The more general discussion of principles underlying 
Sanitary Science lias been crowded into the background by 
the pressure of special features or bearings of the subject, 
but the present period marks another transition;—that is to 
say, we move again toward general principles. The de- 
mand of the times is for an investigation and explanation 
of the efficient nature and modes of propagation and perpet- 
uation of the material causes of disease—epidemic disease, 
especially. To bring the fact forcibly to mind I may refer 
to that great unsettled theory which numbers among its 
adherents some of the great minds of the age, and which, as 
given, is yet too full of inconsistencies and absurdities to 
make a greater claim upon our acceptance than that of an 
hypothesis, the germ theory of disease. Now this theory 
has a practicable, a strong side—ope that will bear the 
closest scrutiny, which may be stated as follows: (1) The 
atmosphere is filled with germs, innocent’ inocuous, con- 
serving the purposes of nature as agents in the decomposi- 
tion of vitalized matter; (2) the normal germ never at- 
tacks vitalized matter; (3) having attacked dead matter, 
and been propagated in it, it becomes an abnormal germ, 2 
capable of disseminating the noxious element of the matter 
in which it is propagated; (4) the normal atmospheric 
germ, it is safe to say, never did and never will cause dis- 
ease; while, it is equally safe to say, the abnormal, noxious 
germ of decomposition, always has, and will cause disease. 
Thus much from the discussions upon the subject may be 
accepted as proven, and nothing else. 
But, admitting all that critical science of the present 
time may admit regarding the germ theory, or any other 
theory of standing, we have still to face the question as to 
the prime cause of disease, and thus Ave turn again to 
general principles. 
No theory yet explains the causes of the widespread de- 
pression of vitality which invariably attends prevalent epi- 
demics of degenerative or zymotic type; if it did Ave should 
know why, during certain seasons, all, or nearly all, acute 
diseases are asthenic in character; or in another case why 
they are sthenic. No theory yet explains the cycles of epi- 
demics; if it did the labors of those in sanitary authority 
would be simplified, and not so easily misdirected, and the 
prognostications of physicians Avould be more certain and 
satisfactory. 
It is no new belief that is urged, nor is it one that is un- 
tried, or unheeded, or unappreciated, to some degree, but it 
is, so to speak, undefined, and unconsciously applied. Sur- 
geons are painfully aware of larger losses during certain 
years or seasons, operative procedures being of similar na- 
ture and grade of severity, and no less skillfully per- 
formed;—the varying results are unaccounted for. Physi- 
cians observe tendencies to types of disease, and upon them 
prognosticate their epidemic or leading remedy; they admit 
into their prognostic estimates the diurnal A'ariations of in- 
tensity of morbid action—exacerbations and remissions; 
they admit the results of climatic and thermal Aricissitudes, 
of atmospheric perturbations, of the presence or absence of 
ozone, of the excess or deficiency of positive atmospheric 
NATURAL LAW APPLIED TO ETIOLOGY. NATURAL LAW APPLIED TO ETIOLOGY. 
3 
and negative terrestrial electricity; and yet with how little 
of the clear understanding so necessary to practical appli- 
cation, how little of that inexorable logic which deduces 
from demonstrable facts! 
I shall not presume to present an ultimatum upon these 
topics, to equalize all inequalities, nor to make logical all 
that is illogical, but I do hope to indicate a means for a 
scientific determination of every question indicated, and 
with them a host of others more or less subsidiary. 
Why do certain diseases become epidemic? Because, 
1st, Preceding or simultaneous with the major epidemics 
there are wide-spread states of depression of the animal 
powers, which determine marked susceptibility to the con- 
tagium of the prevailing disease, i believe the experience 
of every observant physician will substantiate the proposi- 
tion. Perhaps the most noticeable instances are during 
epidemics of typhoid, malarial and yellow fevers, cholera, 
dysentery and diphtheria. Tissue degeneration is a marked 
feature of them all, and during their prevalence most cases 
of acute disease, especially if attacking similar tissues, pre- 
sent, in some degree, characteristic features of the type. 
Nor is this all. Wider observation must demonstrate the 
fact that states of relative good health, during the reign of 
these depressing influences, are degraded. 2d. Because 
the morbid element finds in the prevailing conditions of 
degradation the conditions most congenial to its propaga- 
tion and perpetuation. This, in the very nature of things, 
is a necessary consequence. For, the preceding being true, 
there is no longer the normal degree of vital power in ani- 
mal bodies, so, of course, there is no longer the normal 
degree of vital resistance, or, the more conditions become 
unsuitable to normal vitality, the more they become suit- 
able to morbid action. 
Referring once more to disease germs, it is seen how 
conditions for their propagation are thus fulfilled; for even 
if animal matter with which they are brought in contact is 4 
NATURAL LAW APPLIED TO ETIOLOGY. 
not totally devitalized, it is so degraded as to determine the 
susceptibility so widely recognized, and increasing suscep- 
tibility, more virulent contagium, and greater malignity of 
disease, go hand in hand with, and in strict proportion to, 
the intensity of causes of depression of animal vigor. On 
such grounds it is easily understood why sporadic cases of 
the diseases which are capable of becoming epidemic, do 
not become so; why they manifest so little malignancy; 
why they are so little contagious, and why little or not at 
all infectious. While, therefore, it may not be strictly true 
that disease never is caused by germs it does appear to be 
true that disease never is caused by germs except they have 
been propagated in a diseased tissue, the specific character 
of which they represent. 
From such premises it is difficult to avoid the conclusion 
that animal bodies are responsible, in the second instance, 
for their own morbid states,—the first depending upon the 
external conditions referred to. Spontaneous or self-gener- 
ating specific diseases are not strange to the experience of 
any practitioner, puerperal septicmmia, specific parotitis, 
scarlatina, and diphtheritic angina have fallen under my 
own observation, for the cause of which I unhesitatingly 
deny exposure to an infected atmosphere, to contagious 
germs, to foreign agencies of any and every sort. It is 
very easy to say we don’t know about these exposures;—I 
say we do know it is our business to know. The proof is 
within our reach in our ability to trace backward to the 
very depraved functions and tissues which gave rise to such 
objective signs. It may be concluded, then, that behind all 
the manifestations of the specific diseases, there are forces 
not acting at equilibrium, conditions not neutralized by 
others, the results of the operations of which are pheno- 
menal, and as far as the individual is concerned, degenera- 
tive and destructive. 
Therefore, I believe that the ultimate causes of epidemic 
diseases will be found to be in the abnormal or unusual NATURAL LAW APPLIED TO ETIOLOGY. 
5 
operations of the natural forces; that these induce in ani- 
mal bodies states of depression, unusual susceptibility, and 
tissue degradation; that these in their turn breed their own 
morbid action, or lay the individual open to onsets from in- 
numerable disease elements, material or otherwise, including 
germs. The forces concerned in these results are: 
1. Electricity, with its modifications, positive, negative, 
magnetic and ozonic; and its transformations or correlatives 
heat and light, with their modifications. 
2. Gravitation, with its modifications. 
3. Atmospheric Pressure, with its concomitants. 
Whether it is true or not, as some meteorologists claim, 
that all the great atmospheric and oceanic currents are 
caused by the expansibility and rarefaction of heated mat- 
ter, it is a fact that electricity is an ever-present active 
factor, and its activity is modified and its potential varied 
Avith every change that occurs in the movements of the air 
and the ocean. Instability, then, is characteristic of elec- 
tricity. It is true, further, that atmospheric electricity is 
always positive, and that the symbol of its power may be 
increased or diminished; hence its intensity is variable. 
But as its power is relative merely, being measured from a 
standard of neutrality, it appears that the less positive con- 
ditions become the more negative. Noav it can be shown 
that positive electrification is the necessary normal condi- 
tion of a healthy invigorating atmosphere, and that in the 
same degree that its amount becomes diminished, or is 
neutralized by the accession of negative states, in the same 
degree does it become abnormal and devitalizing. 
It is an extraordinary fact that all manifestations of life 
have as a condition the e\rolution of positive electricity. It 
is also true that negative states and animation are absolutely 
incompatible. This condition of living bodies is a variable 
one, and that independently of external influences. Now 
if the electrical norm of a living body is degraded from 
causes within itself, and in addition is subject to further 6 
NATURAL LAW APPLIED TO ETIOLOGY. 
degradation from the neutralization of the atmospheric posi- 
tive state, which is a source of supply independently of 
bodily sources, it is not easy to avoid the conclusion that 
these causes, one or both, operate as predisponents to mor- 
bid action. Further, the same conditions prevailing over 
wide areas, and through long periods of time, as they un- 
questionably do, we are furnished with the cause of the 
states of least resistance or depression of vitality which is 
so constantly an element of pestilential activity. Admitting 
deficiency, we must admit excess, and doing so we account 
for the prevalence of the acute inflammatory, or sthenic dis- 
eases, as well. 
Magnetism is classed as a modification of electricity, yet 
I believe the terms to be conditionally convertible; for it 
seems to me that they are forms of the same force opera- 
ting under different circumstances, that is to say, magnetism 
belongs to the universe is the bond of union of its mem- 
bers, while electricity belongs to the atmosphere of the 
earth, and to it alone. In short, electricity is mobilized 
magnetism; or, magnetism is mobilized static electricity. 
Its origin being in solar activity, and its influence including 
every body in our system, it is seen that its consideration 
must include too much solar and planetary physics to be 
brought within the limits of this paper. It may be said, 
however, that to it, in the end, may be brought home each 
and every point. 
Notwithstanding the conflicting opinions regarding 
ozone, I am disposed to adopt that of Prof. Kedzie, who 
says: “I call ozone the most energetic of the constituents 
of the atmosphere. Its presence or absence must have a 
controlling influence over the vital powers, and it seems to 
me that no one can deny that its influence on human health 
must be most significant.” Flippant denial of its existence 
in a normal atmosphere is easily made, but the results of 
observations by men of world-wide reputation and of unim- 
peachable standing in the scientific world, place it beyond NATURAL LAW APPLIED TO ETIOLOGY. 
7 
the reach of irresponsible denials. The lights of such ob- 
servers as Shoenbein, Faraday, Boeckel, Dove, Moffatt, 
Lowe, Day, and Tyndall, cannot be incontinently snuffed 
out. From among the multitude of facts concerning this 
agent, one only is selected for this occasion, and that more 
for the purpose of giving it the emphasis which it deserves, 
than to enter a discussion on it. Adopting the definition 
of the action of atmospheric ozone, some consideration is 
due to the circumstances attending its appearance and dis- 
appearance. The transformation of simple oxygen into a 
substance having such peculiar chemical activity, takes 
place under the action of free atmospheric electricity. If 
there is little or no free electricity in the air, then little or 
no metamorphosis of oxygen occurs. Such being the fact 
we are able to say pretty definitely in what conditions of 
the atmosphere ozone is present, or otherwise. At the out- 
set we are struck with the remarkable complementary rela- 
tions existing between meteorological conditions and those 
which determine the presence or absence of ozone; for, 
whereas, in the one case there is high barometrical pres- 
sure, with cooler, purer, highly electrified air being poured 
down upon the earth’s surface from the upper regions, 
bringing with it free electricity in abundance; in the other 
case opposite conditions prevail;—a heated, attenuated, 
vapor-laden atmosphere at a low pressure, which has ab- 
sorbed not only the free electricity, but has greatly neutra- 
lized the electrically positive state of the air, in the vapori- 
zation of the water which it contains. Under the first class 
of phenomena ozone is generated; under the other it is not 
only generated, but that which is already present is decom- 
posed to furnish the electrical force essential to the process 
of vaporization. Between these opposite states of the at- 
mosphere lies all the difference between health and disease; 
for the phenomena of one side are conservative and protec- 
tive, and on the other they are destructive. 
It must occur to our minds that with the atmosphere at 8 
NATURAL LAW APPLIED TO ETIOLOGY. 
or near its mean or electrically positive state; with a suffi- 
cient quantity of free electricity to subserve the processes 
of evaporation and the generation of ozone in sufficiency to 
oxydize organic noxious emanations or miasmas; with an 
equilibrium between the positive atmosphere and the neg- 
ative earth; with equalization between the sometime elec- 
tro-positive antagonisms of animal life and the atmosphere; 
and with such relations of polarity between the animal and 
the earth as to preclude violence, that animal life is at its 
highest point of conservatism. Now every condition speci- 
fied may be reversed, or any one of them; some may oper- 
ate with extreme violence, others far below the mean or not 
at all. Is it not apparent that with fluctuations of these 
mean states the vitality of every living thing has such a tax 
laid upon it that, instead of its powers of existence alone 
being called into the account, its powers of resistance are 
laid under contribution as well? But suppose these dele- 
terious fluctuations extend through long periods of time, 
and over wide areas of the earth’s surface;—must the fact 
be again emphasized that this is one of the prime conditions 
of a wide-spread epidemic state? 
For instance:—It is recognized that the general char- 
acteristics of human constitutions are not types each of 
another, bat that elementary variations occur. So marked 
is this peculiarity that arbitrary classifications have been 
found necessary to express it. Since members of these 
classes began as they continue, we infer that some pre-natal 
influence has determined the peculiarity. Such influences 
should undoubtedly enter into our estimates of individual 
predisposition, and we are bound to enquire into the origin 
of them. Now suppose that over a specified time and place 
such conditions are prevailing that the vitality of human 
beings is depressed in a peculiar manner. An inference is 
that pregnant women are vitally depressed also, and that 
their offspring will receive the same or similar morbid im- 
pressions, and are, therefore, predisposed to states of low NATURAL LAW APPLIED TO ETIOLOGY. 
9 
vitality. Whether the “constitutions” of writers may he 
thus in part explained, or not, it certainly offers a plausible 
explanation of some epidemics among infants. 
It would be unprofiable in the present state of knowl- 
edge upon the subject, to enter upon speculations regard- 
ing the relations of light and heat with states of health, but 
in the investigations of the future they will not pass un- 
heeded. L'ujht may be dismissed from present considera- 
tion with a single remark: As its source is fluctuating, so 
it must vary in intensity; as physical existences are condi- 
tioned to a mean of its intensity, according to the latitude 
in which they are placed, so their vigor is or is not main- 
tained according as the supply departs or not from a mean 
intensity. More should be said regarding heat, but it, also, 
must be dismissed with little remark. From the fact that 
the extent and prevalence of such diseases as yellow fever, 
typhus fever, phthisis pulmonalis, and catarrhal diseases, 
are more or less rigidly marked by degrees of north and 
south latitude, it follows that deviations from common 
thermal intensities within these ranges must be coupled 
with advancing or receding averages; and the vicissitudes 
along the borders of these regions should mark a narrower 
or wider prevalence of these diseases. 
The other topics, atmospheric pressure and (/cavitation 
must remain for future consideration, as well by reason of 
the tax upon the society’s patience, as on account of its in- 
flexible rule which protects against the infliction. Suffice 
it to say that the grounds are as strong as in the case of 
electricity for supposing that their normal or abnormal 
operations maintain or disturb the plane of healthful life. 
So similar, indeed, are the effects of their variations to 
those already considered, that what may be said of one, is 
true of the others. In fact, a compound gradient may be 
formed, which may embrace each element, to rise and fall 
above or below an assumed mean, and which unerringly 
indicates departure or otherwise from a standard of health. 10 
NATURAL LAW APPLIED TO ETIOLOGY. 
Finally, to bring the whole subject within the realm of 
professional respectability, I can do no better than quote 
from Prof. Richardson’s Diseases of Modern Life: “With- 
al, there is a general, if unwritten, knowledge, that certain 
marked events of disease, are often found occurring together, 
as if they depended upon some common influence. There 
are epidemic visitations. There are accumulated instances 
of death from apoplexies, hemorrhages, congestion 
of the lungs, failures in the motion of the heart. The op- 
erating surgeon has a long run of successful operations, 
even of severe operations; then he has a long run of fatal 
operations, in which he knows that the severity plays no 
part in the general result. When we put all these facts 
together, though we even call them coincidences, for want 
of a better term, they point circumstantially to the limita- 
tion of the phenomena of disease, and to the dependence 
of these phenomena, however apparently varied, upon the 
operation of a few causes, active and external. The external 
causes which give rise to the phenomena of disease have 
remained steadily in operation, producing repetition of the 
phenomena in such systematized order, that from patient 
study of history we might predict the recurrence of some 
of the phenomena, as astronomers predict the return of 
comets and the recurrence of eclipses. The causes have 
remained unchanged; the phenomena have followed with 
the precision of natural law.”