PERSPECTIVE VIEW 
SOUTH WEST 
2 X- 6 Kntn- Ctoxfts 
3 .*• 4 Son itur i - Hm/tHnt/s 
7. /.Hurting 
HOFFMAN ISLAND GENERAL PRINCIPLES 
AFFECTING THE 
ORGANIZATION OF QUARANTINE. 
A PAPER READ BEFORE THE NEW YORK ACADEMY OF MEDICINE, IN 
DECEMBER, 1873, AND, BY RESOLUTION OF THE MEDICAL 
SOCIETY OF THE STATE OF NEW YORK, REQUESTED 
FOR PUBLICATION IN ITS TRANSACTIONS. 
BY 
S. OAKLEY VANDERPOEL, M. D., 
HEALTH OFFICER OF THE PORT OF NEW YORK; LATE PRESIDENT OF THE MEDICAL SOCIETY OF THE 
STATE OF NEW YORK; HONORARY FELLOW OF THE NEW YORK ACADEMY OF MEDICINE, ETC. 
NEW YORK: 
D. APPLETON AND COMPANY, 
549 & 551 BROADWAY. 
1874. GENERAL PRINCIPLES AFFECTING THE ORGANIZATION 
OF QUARANTINE. 
The consideration of the subject of quarantine is based upon the no- 
tion that there is a class of blood-poisons which are transmissible. It is, I 
believe, admitted that there are those of a strictly endemic character, de- 
pendent upon local conditions, and, with the exception of typhus fever, 
rarely extending beyond the influence of those conditions. With this 
single exception they are not contagious, or, to use a more fashionable term, 
in place of one which, since the days of Frascator, has done good service, 
and explained succinctly the idea intended to be conveyed, they are not 
transmissible. 
There is, however, another class, which may be termed exotic in origin, 
and to prevent the importation or transmission of which, quarantine, in 
one form or another, was long since established. Limited both in num- 
ber, and in the extent of territory in which they are indigenous, they 
assume a virulent !tnd specific character, become transmissible to persons 
not exposed to the primary influence, and extend over vast portions of 
the inhabitable globe, and, after raging epidemically for a period, subside 
sometimes, it would seem, from mere lack of material for further ravages, 
or at another as if the primary germ-power had become exhausted. Com- 
ing as they do from localities outside of European or North American 
centres of population, their approach is always regarded with grave ap- 
prehension ; and from the earliest periods we find each country, each dis- 
trict, or it may be each municipality, devising restrictive measures to pre- 
vent their ingress. The plague, yellow fever, and cholera, are the three 
diseases included in the above description. From the first named this 
country has been wholly exempt; yet from the fact that it has repeatedly 
been a fearful visitant over large portions of Europe, and that the restric- 
tive measures adopted for its prevention, running through centuries, were 
the bases of all later ordinances to prevent the spread of yellow fever and 
cholera, I shall be compelled to refer constantly to them in the discussion 
of the question. Fortunately, in the organization of measures at this 
port, the traditions, and oftentimes senseless regulations, which resulted 4 
from blind and fanatical populations in Europe, were not all-powerful to 
control their formation. Still the traditions of the past can everywhere 
be seen, sometimes affording valuable light to direct present operations, 
and sometimes, by an effort at blind uniformity and fixed regulations, pre- 
senting stumbling-blocks, which would be to the sanitarian so many causes 
of offense, and obstructions to all real progress. 
I am aware that the subject is one rarely brought to the attention of 
a medical audience; yet if you recall for a moment that in its considera- 
tion are involved the most delicate questions which hygiene presents, that 
we must study the origin, progress, and methods of dissemination of con- 
tagious diseases, in order that we may intelligently limit them, you will 
see that it is intimately germane to all hygienic studies. 
The name of quarantine is given to the measures of isolation imposed 
on persons and cargoes, susceptible, on account of their passage or their 
contact with persons or contaminated objects, of transmitting an epidemic 
or contagious disease of exotic production. Originally the word indi- 
cated the limit of time (forty days) that individuals suspected of exposure 
to pestilential contagion should be placed under observation. It no 
more expresses the duration of this trial; and now, in ordinary parlance, 
as well as special sanitary expression, the word quarantine expresses prin- 
cipally isolation and sequestration, without reference to the duration of 
the application of these measures—a duration which has varied so fre- 
quently according to the particular period, which varies still in different 
places, and which varies especially according to the nature and the dif- 
ferent conditions of danger recognized in those exposed. It comprises, 
then, more specially, the whole series of restrictive measures destined to 
prevent the march of an epidemic or contagious affection. There are 
other measures, not strictly included in the above, whioh serve to complete 
this system, in acting not as barriers against the threatened scourge, but 
rather as modificators of the particular district threatened, in which are 
involved all hygienic precautions. For the march of every affection trans- 
missible by man is in reality subordinate to two conditions, each of which 
plays an important part: x. The contagion, more or less intense, no matter 
what may be the vehicle. 2. Amount or degree of receptivity of the 
threatened population, of whom the immunities or morbid predispositions, 
sometimes inappreciable in their intimate cause, are, however, usually refer- 
able to the hygienic conditions of the population. 
Since the end of the last century, however, we see observers of merit 
inveigh against the doctrine of contagion, and consequently the practical 
consequences thence arising. These would be the suppression of quar- 
antines, the abolition of all impediments which might obstruct commerce, 
and the free circulation of travelers and merchandises. This is not, then, 
a discussion purely scientific, which amuses only cultivated intellects, 
having little practical results ; on the contrary, an affirmative or negative 
solution would, on the one hand, paralyze all efforts, or, on the other, im- 5 
press upon them a determinate course. For, if the origin of epidemics is 
to be ascribed to cosmic, telluric, or individual causes, over which we 
cannot hope to exercise any influence, we must be resigned to them, and 
support them with the same patience as we do the summer heats or win- 
try storms.* This idea has its practical application in the respective meas- 
ures taken by England and France with reference to the cattle-plague. 
Breaking out as it did about the same time in both countries, the resultant 
effect of different action is readily noted. The French veterinary officers, 
convinced of its contagious character, took immediately the most vigor- 
ous measures to strike at the root of the evil. It was necessary to slaugh- 
ter promptly about a hundred animals to put a stop to the progress of the 
epidemic. In England, the anarchy of opinions, as well as imperfect 
legislation, allowed things to follow their natural course. The result was, 
that three hundred thousand animals died from the disease. 
It is, then, of the highest importance to have decided opinions upon 
the subject: to wait until an epidemic is upon us, is to wait for precau- 
tionary measures after our building has been fired. Individual facts have 
more than once shown that the arrival of a single sick person in a locality, 
up to that time intact, has developed the epidemic. It is the initial case 
in which lies the chief danger; nor can I recall a better illustration of 
this than the facts presented by Dr. Peters in his researches upon the 
cholera in Lexington, Kentucky, during the past summer. Thirteen 
deaths occurred, before that of the initial case, every one of which was 
traceable to causes emanating from that case. I may mention here as at 
least a recognized fact, that all epidemics follow the routes, and with the 
same celerity as those who travel upon them. 
On these points it will at least be found that clinical observation, in- 
ternational hygiene, and direct experiment, are in full accord with the 
teachings of traditional medicine. 
With this preliminary statement, I proceed to a more systematic dis- 
cussion of the subject. 
i. All restrictive measures, isolation, quarantine, or, as practised in parts 
of Europe, the “ cordon sanitaire,” have exclusively as their purpose, 
often indeed at the expense of human liberty, to trammel the propagation 
of the morbid cause. Local hygienic measures are intended to render a 
district, so to speak, refractory to the action of this cause, by not present- 
ing the materials favorable to such propagation. Unfortunately, these two 
courses have been, on the part of some, considered as two distinct methods, 
antagonistic the one to the other. The first, that is, restriction, has been 
extolled beyond measure by the contagionists, as sufficient. They only 
see, in every epidemic propagation, a series of morbid acts, fatally imposed 
on many similar organisms by the contact of a specific germ. The sec- 
ond, the pure hygienist, is the device of the partisans of morbid sponta- 
neity, of the anti-contagionists, who, not content to recognize the enormous 
influence which the local conditions possess upon the germ, forget that we 6 
often see epidemics propagated in most salubrious localities, and conse- 
quently that we must oppose to transmissible affections other obstacles 
than those ordinarily included in mere hygienic principles, which alone 
can never confer upon the masses of a population an immunity compar- 
able to that of lessening or rather excluding the cause. Each system 
errs in creating an exclusivism, because first, the method of absolute re- 
strictions is contrary to the dignity of man, by the frequency and the 
abuse of the sequestration which it imposes. It is contrary also-to the 
well-being and health of a people, in neglecting to guard against the dan- 
gers which arise from the collections of filth, the true local nests of every 
infection. Yet to-day we see this exemplified in all the Spanish, Italian, 
and many Eastern ports, where it constitutes the only safeguard in times 
of great epidemics. We know full well that, in most of these countries, 
the moral wretchedness of the people equals their physical, that above all 
else they are blindly superstitious, and attach themselves to measures of 
quarantine sequestration with the fanaticism of all their other beliefs, 
and are ready at the first indication to sustain them by the most violent 
and blinded acts. 
2. The method of local prevention by rendering healthy the threat- 
ened locality, in ameliorating all the social conditions of the inhabitants, 
is, in itself alone, more specially adopted by a civilized people. It has 
this immense advantage, of inaugurating and establishing for a community 
an era of comfort and prosperity. You are all aware how much England 
owes to her immense works, undertaken, upon hygienic bases, within the 
past ten years. Thanks to these labors—thanks, also, to her natural iso- 
lation from the Continental masses; still more, thanks to certain climatic 
conditions—Great Britain can, with impunity, maintain the free pratique 
of her ports. To attribute her immunity against different pestilential dis- 
eases to the happy effects of hygienic measures, is to encourage every 
nation or community with whom the principles of hygiene have not yet 
become practical; but, in so doing, only one of the reasons of this immu- 
nity is recognized : the importance of climatic and topographic influences 
upon the march of epidemics is forgotten. In France, where public hy- 
giene has made great progress—in this country, which will soon surpass, 
in this respect, the civilized world—owing to the special conditions of ge- 
ography and climate, it is necessary to adopt, against the propagation of 
epidemics, a more complete system of prevention. They must first ob- 
struct, by restrictive measures, the propagation of the morbid germ; and, 
secondly, render, as far as possible, each locality refractory to its develop- 
ment. In both France and this country we have the daily proof that the 
two methods, in place of mutual exclusion, should be combined, in order 
to unite the double base of international and municipal prevention. 
So far from opposing each other, these methods mutually complete a sys- 
tem ; and now, at this port, the system of quarantine embraces the whole 
series of prophylactic measures opposed to the propagation of epidemic 7 
diseases, it matters not whether the measures have for object the opposing 
of the transmission of the morbid germ, or whether only to hinder its de- 
velopment by hygienic labors. From this happy accord results a sanitary 
regime more complete and more rational, and where we can, according to 
circumstances, apply the one or the other element. Quarantine restric- 
tions, so senseless and imperfect heretofore, have drawn from prophylactic 
hygiene the fundamental principles of their actual working. 
The truth is, the question of quarantines is one of the most complex 
of hygiene and medicine. If you bear in mind the obscurity which still 
hangs over the conditions of the development of epidemics ; if you recall 
that, upon the globe, there is not a continent—that, on such continent, 
there is not a country—which does not present different conditions of 
predisposition, or immunity, with reference to these scourges; if, further, 
it is remembered that every quarantine system, while it confers advantages 
upon those it protects, involves grave prejudices for those it contravenes, 
you will understand how difficult it is to express, in determinate adminis- 
trative formulas, regulations applicable to every place. The joint respon- 
sibility so necessary among localities, since the most rational or the most 
absolute measures undertaken in one country can be annulled in their re- 
sults by the indifference of another, will, for a long time, be difficult to 
obtain. To be scientific and practical, they should necessarily arrive at 
conclusions variable according to the locality or port to which the regula- 
tions are to be applied ; variable, also, according to the nature of the dis- 
eases they propose to contravene. These regulations will then, by their 
diversity, recall how varied are the dangers they should prevent, and also 
how different is the morbid receptivity of the different populations which 
they are to protect. It is not difficult, then, to comprehend how essential 
it is that the great question of sanitary measures should become more and 
more the privilege of competent men—of men who understand the mode 
of propagation of epidemics, the local and geographical conditions of their 
development, and the special prophylactic measures applicable to each. 
Rules established by tradition and custom have, without doubt, thanks 
to their uniformity, great facility in their practical application. But 
always to impose the same rules, in the most diverse conditions of time 
and place, as well as the nature of the epidemic designed to arrest, would 
be to act contrary to all our scientific data. Too long has this reform been 
retarded by the traditional errors drawn from European regulations, and 
we have, in this country, the opportunity to disembarrass ourselves from a 
host of practices inspired by secular prejudices common in Europe. 
While, then, true prudence should cause us to abstain from bringing the 
same regulations to the prevention of all pestilential diseases, the forms and 
modes of propagation of which vary so wholly, according to the places in 
which they are observed, we are not so embarrassed in determining the 
nature of the establishment required. Sanitary establishments have to- 
day their types, indicated by physicians and hygienists—types which can 8 
be reproduced and, as occasion requires, perfected. Not so, however, the 
regulations. You cannot give to all ports the same mode of application. 
In one city there may be topographical or social conditions which modify 
the degree of morbid susceptibility in the different classes of the popula- 
tion. In fine, no absolute, no arbitrary rules can be formed, suitable for 
every latitude, every clime, or every people. 
There is still another class of influences, irrespective of locality and 
the different forms of the pestilential' diseases. They are the particular 
features of the epidemic itself, so variable at each explosion. When, for 
instance, we see one of these affections cover, so to speak, the entire world 
in its manifestations, or, at another time, as a circumscribed epidemic— 
when, in following out their history through a course of centuries, we see, 
at one time, the plague, at another, cholera, or, again, yellow fever, play 
successively the principal part in the scourges which decimate populations 
—we are certainly compelled to recognize the variability of the conditions 
of development of epidemic diseases, and consequently the inequality in 
the character of the protective measures. 
It seems to me, you will best appreciate the different bearings of this 
subject by tracing, for a few moments, the origin and progress of the prin- 
ciple I have stated, and which controls the administration of this branch 
of sanitary science. The idea of the transmission of diseases by contact 
is one which dates back to the farthest antiquity. The minute prescrip- 
tions by which Moses sought to isolate, even in the midst of his camp, 
those attacked with leprosy, or other diseases which he supposed conta- 
gious, would indicate that already, with the ancient Egyptians, this first 
notion had been universally accepted. 
Still the first account we have of an epidemic propagated from conta- 
gion is not by a physician, but by the historian Thucydides. The plague 
at Athens is the first known of these formidable affections which, coming 
from without, fall suddenly upon an entire population, snatching innumer- 
able victims. In the march of this epidemic we find the principal charac- 
ters which at different times have been met in all subsequent incursions. 
Overcrowding, wretchedness, hunger, were shown among the predisposing 
causes, and which ever since have been known to favor the development 
of these fearful scourges. The fact, too, was established, that its way of 
entry was by the sea, the chief route for epidemics to enter a country. 
It was not, however, until the appearance of the plague in i348-’5o, that 
the regime of quarantine against pestilential affections was fully inaugurat- 
ed. As for ages previous leprosy had been the principal disease in which 
isolation was ordered, we see, in looking over the regulations which existed 
in many of the places on the shores of the Mediterranean, that they were 
those adopted with regard to leprosy, save that the definitive isolation of 
the one was changed to the temporary sequestration of the other. About 
this period the recurrence of grave pestilential epidemics inspired the 
public, rather than physicians, with the notion of their transmissibility by 9 
those attacked. As a consequence the restrictions were marked by the 
brutal and superstitious spirit which characterized the age. The murder- 
ing of physicians, the bloody persecutions against the Jews, self-imposed 
tortures by individuals to propitiate Divine mercy, witness the superstition 
and barbarity of the epoch. 
Soon it was noticed that vessels and passengers coming from the East, 
though not attacked themselves, brought with them the morbid germ. 
Venice, rising from her lagoons, was then the most enterprising and chief 
commercial city of the world. Covering the Mediterranean with her 
vessels, she made at the same time commerce and war; consequently, her 
port more than any other was subject not only to the black plague, but 
especially the Egyptian, then so frequent in its explosions. Induced by 
their frequent appearance, she proscribed the sale and destroyed the effects 
of those who had died. She created three protectors of the health, a 
health bureau, and finally a lazaretto, which subsequently formed the 
model for all other ports. 
Her example was followed by all the smaller places on the Adriatic 
coasts, existing then as separate governments. It is probable that the ter- 
ror inspired by the repeated visitations of the pestilence gave rise to that 
persistent hostility to strangers which still exists in many portions of 
Southern Italy. From this time, too, dates the period of forty days as ne- 
cessary for the examination of suspected persons. Another fact of interest 
in this connection is, that for the first time medical men, not only by the 
aid of scholastic arguments, but by the study of facts, interested themselves 
in the question, “ how far contagion was concerned in the transmission of 
the plague ”—as the result of these inquiries, running, it is true, through 
a long series of years, for after the disappearance of each scourge precau- 
tionary measures were laid aside, to reappear more absolute at the ap- 
proach of new danger. 
About the middle of the sixteenth century the celebrated work of 
Frascator appeared. It is the first work which speaks of contagion as 
now understood. According to him, a specific virus rises by exhalation 
from the body of the sick, extends but a short distance, attaches itself to 
certain substances, which thus become contaminated ; this contamination 
remains and may be transported unknown distances and infect entire com- 
munities. He recognizes also that certain other substances would not be 
contaminated. The public mind seized eagerly upon this distinction of 
contamination and non-contamination, the decision of which has been the 
source of so many discussions and such diversity of opinions. Indepen- 
dent of his natural exaggerations, his work wrought this double advantage: 
i. To show certain real dangers not before suspected, and recall to ration- 
al observation many minds, misled by the belief in the influence of the 
stars, or by their faith in the Galenist dogma of occult causes. 2. To dis- 
pel, on the other hand, that which was equally difficult, certain prejudices 
which exaggerated the property of transmission of such diseases and ad- 10 
mitted that they could be communicated by voice and expression of the 
sick. This opinion was still more fortified by a subsequent work by Ma- 
saria, who showed the immunity of persons who, during an epidemic, had 
remained shut up in their chateaux or in monasteries. He limited the 
ravages, in isolating the sick outside the city. The success which followed 
this advice made his work an article of faith, and it was followed by the 
organization of similar establishments in all Mediterranean ports. 
From the beginning of the seventeenth century Europe found herself 
relative to the plague in analogous conditions to those in which we are rela- 
tive to cholera. The disease had reached its maximum of diffusion through 
the civilized world, and was especially terrible in all the large capitals. 
Sanitary police were established in all or nearly all, and the most vigorous 
measures were adopted for the sequestration of those stricken. Both local 
and general authorities acted in concord, the one in defining the move- 
ments and restrictions of the inhabitants ; the other in surrounding the 
pested city with troops, to prevent ingress or egress except under definite 
regulations. The spirit of isolation was carried to such extremes that 
without doubt the scourge was intensified, by compelling the inhabitants 
to remain in the infected districts, and often- by the inadequate supply of 
food to those so subjected. Fumigations were also liberally practised in 
all suspected localities, and also by physicians in making professional vis- 
its, but the articles employed were more marked by the pungency or spe- 
ciality of odor than by any true disinfecting property. 
The eighteenth century was marked by the more decided use of laza- 
rettos. The result was soon observed; the disease declined from the in- 
terior portions of Europe, and was chiefly confined to the maritime ports. 
The regulations assumed a more explicit and in some sense rational form, 
though the penalties were very severe, and enforced with intense rigor. 
Explicit directions were given to all vessels trading with Egypt or the Le- 
vant, not with reference to passengers only, but also the cargo and the ves- 
sel itself. The increasing commerce of France with the East gave the port 
of Marseilles an especial prominence, and its lazaretto became the most 
celebrated in Europe, not only in the care manifested, but, as knowledge 
existed, the best conducted. It enjoyed, too, the confidence of the citizens, 
by several times restraining the contagion from the city after its entrance 
into the lazaretto. 
To one familiar with the history of the subject, it is interesting to study 
the minute distinctions made not only with reference to the bill of health, 
but the measures of observation taken with reference to passengers and 
merchandise—measures which, while they might protect the community, 
lost sight entirely of the rights and privileges of those suspected; and 
which, were there the least trace of fomites in the vessel or cargo, would be 
certain to communicate to the poor unfortunates, who were compelled to 
undergo an almost unlimited period of observation. During the latter part 
of this century observations were more carefully and systematically insti- 11 
tuted, and the modes of propagation of the scourge more accurately noted. 
Chief among these was the great philanthropist John Howard. He visit- 
ed successively the hospitals and lazarettos of the Mediterranean where the 
plague prevailed; attacked energetically the defective appointments, es- 
tablished the importance of the hygienic conditions in these establish- 
ments, sustained the inutility of quarantines imposed on merchandise, and 
really laid the foundation for the present English legislation on the subject. 
He dispelled the idea that the corpse could communicate the disease; a 
point of great importance, since in many epidemics they were allowed to 
accumulate unburied, people flying from them in terror. He combated 
also the foolish and grotesque precautions taken by physicians and nurses 
to escape immediate contact with the sick, and dispelled the illusion that 
the contagion could be conveyed by their breath. 
During the early part of the present century, the doctrine of quarantine 
was affirmed with renewed energy, and the privileges accorded were, if pos- 
sible, more decided; gradually, a more exact appreciation of facts induced 
a more eclectic tendency, preserving that which was useful, and rejecting 
that which was exaggerated. We notice, too, in European governments 
the first steps taken to stifle pestilential maladies in their place of origin, 
which resulted in the international congress to consult upon the principles 
to be laid down in order to prevent their wide-spread diffusion. 
An additional interest arises in their study, from the modification of 
the list of diseases to which restrictive measures should be applied. Up 
to the commencement of this century, no other disease than the plague had 
occupied the attention of quarantines. From 1821, however, the interest 
in this disease gradually subsided, to be replaced, in a far greater degree, 
by the questions of yellow fever and cholera. During the few years pre- 
vious to this the anti-contagionists had inveighed severely against all 
restrictive measures in yellow fever, asserting that it could not be im- 
ported, and that those who thus affirmed were men without experience, 
obstinate, and of limited information. Scarcely had these positive opin- 
ions been enunciated, and even obtained some credence in public senti- 
ment, when the terrible scourge of yellow fever, which invaded Barcelona 
in 1821, appeared. Its transmission by sea was undeniable; reaching the 
quarantine of Marseilles, it was excluded from that city. . 
For the cholera a different order of circumstances presented. The 
danger to be apprehended here was not from the side of the sea, but from 
the land. For years European governments had watched the progress of 
the Indian scourge, the terror inspired by its ravages in Asia, and had 
hoped to arrest its progress on the Russian frontier. It was thought that, 
by creating a “ cordon sanitaire ” on the boundaries of each country, its 
progress could be arrested. Various restrictions to intercourse were 
established* virtually establishing quarantines by land as well as by sea. 
We all know how useless were these efforts. The rapid march of the first 
cholera epidemic through Europe in 1831, and the fact that it did not ap- 12 
pear in certain countries where no restrictive measures were applied, 
showed the utter uselessness of these cordons sanitaires in thickly-settled dis- 
tricts, and they were soon abandoned. It had the effect to revive the old 
discussions relative to its transmissibility from man to man,- many assert- 
ing that it was wholly epidemic in its character, an argument which had a 
specious force from the rapidity and uncontrollability of its progress. Its 
contagion was treated by them as a chimerical belief; those who opposed 
the idea of contagion were considered truly men of progress, since they 
opposed restrictions to personal liberty, and their views were applied, not 
only to cholera, but typhus and other diseases. These hesitations and 
differences continue more or less still among the different portions of Eu- 
rope. Indeed, the futility of the effort to establish a uniform system of 
quarantine regulations for countries or seaports in different localities, 
having different relations with countries from which malignant diseases 
are brought, is acknowledged there—that which experience had long ago 
taught in this country. 
Matters remained very much in this unsettled state, both as to the 
principles which should govern the administration of quarantines, and the 
varied action of different governments, when, in 1850, a convention, with 
reference to some uniformity of principle, was held at Paris. 
It consisted of representatives from all the principal European powers. 
They were medical men, and with them were associated also the consuls 
of the respective countries represented in France. Discussions of a purely 
scientific character were ignored; confining themselves to facts generally 
accepted, and by the aid of mutual concessions, they arrived at’a code of 
international sanitary regulations, which, though since modified in many 
particulars, have remained the basis of all subsequent quarantine legisla- 
tion. Among them I find many of the provisions of the law now in force 
in this State. I cannot enter into an analysis of its provisions, but who- 
ever reads it carefully will see that it is based upon a study of the cause 
and progress of the diseases which it is intended to intercept, and, almost 
for the first time, places the administration of these establishments in the 
hands of medical men. It is not inappropriate to quote an extract from 
a paper by the Minister of Agriculture and Commerce, written just before 
this convention. He writes : “ The question of quarantine is one of those 
questions of public hygiene which the government cannot decide, and 
which can only be resolved, either by the Academy of Medicine, or the 
Academy of Sciences.” 
The spirit inspired by this convention awakened a new interest and 
enthusiasm on the subject, and was the initiation for the subsequent gath- 
ering at Constantinople some fifteen years later. An energetic impulse 
was given, not only to the study of restrictive measures, but the still more 
important duty, the application of public hygiene to the prevention of 
epidemics, if possible, at the source—to stifle them in their exotic cradles, 
or, at home, in removing the causes by which they are propagated, thus 
each diminishing the zones over which they can spread. 13 
In looking over quarantine legislation as enacted at different times in 
this State, we are first struck with the freedom from the trammels and 
prejudices and formalities which so long marked all European enact- 
ments. Each principle seemed to spring from the practical necessity of 
the occasion, and was generally the result of the experience afforded by 
some epidemic of fever just passed. 
The first legislation was in 1784, and compares most favorably with 
contemporaneous European enactments. Yellow fever was then a fre- 
quent visitant of this port, appearing as an epidemic nearly every year 
during the latter part of the last and the early years of the present cen- 
tury. Another principle, as the result of these repeated epidemics, was 
early established, viz. : that all vessels from foreign ports, and all coast- 
ing-vessels, coming from south of Cape May at certain seasons of the year, 
should undergo sanitary inspection on entering the port. The futility of 
locking the door after the article is stolen was applied to quarantine, in the 
comparative uselessness of restrictive measures after an epidemic had 
gained foothold in the city. The great mistake was, that in protecting the 
community they lost sight wholly of the commercial interests involved. 
True, with navigation at that time wholly in sailing-vessels, time was not as 
important a factor as since the introduction of steam, and vessels and own- 
ers submitted most patiently to the restrictions. It is evident, however, 
that the natural history of the disease (yellow fever) was not fully under- 
stood, or we should have no such clause as this: “Vessels to be detained 
thirty days at quarantine, and twenty days after discharge of cargo. Car- 
goes to be detained subject to the decision of the health-officer. Crews and 
passengers to be detained twenty days after the last case of yellow fever, or 
twenty days after sailing from an infected port.” What would become of 
West India trade if such orders were now enforced ? Yet a- provision, con- 
taining almost similar regulations, stands now in force upon the statute- 
book. The whole tenor, however, of legislation has been to recognize the 
opinions and decisions of medical men in the quarantine enactments ; and, 
as a rule, they reflect the current opinions of the mode of dissemination 
of the epidemics they were .intended to contravene. It is not necessary in 
this connection to recount the present practice with regard to pestilential 
diseases. I need only say in passing, that, as now constituted, the estab- 
lishment is most complete in all its appointments, and fully equal to the 
sanitary requirements of the times. For the present there are still a few 
general considerations connected with the subject to notice before pro- 
ceeding to the study of the special diseases. 
We are now prepared, after a very hasty historical sketch of the origin 
and growth of the systems of quarantine, to consider their prophylactic value. 
I am aware of the varied opinions which exist on this point, both in this 
country and in Europe, of partisans who on the one hand deny all sanitary 
value to their restrictions, and on the other, who claim for them exagger- 
ated benefits. On looking closer at the school which opposes all seques- 14 
tration, 1 find, almost invariably, that their opinions are formed and 
based by the surroundings and climate of their particular locality—sur- 
roundings where, from the nature of their position to neighboring countries, 
no restrictive measures, save those which could be effected by a cordon sani- 
taire (a system found totally inefficient in thickly-populated countries, 
and only applicable in sparsely-settled districts), could be applied ; and, on 
the other hand, countries situated in latitudes where the exotic pestilences, 
all of which find their endemic dwelling in the torrid zone, can, with the 
exception of cholera, find but a short season when temperature and hy- 
grometric conditions would favor their development. 
Such persons, studying alone from their own stand-point, attempt to 
apply general principles for all localities : a fallacy too absurd for contra- 
diction. Quarantines are not essential to the higher regions of the tem- 
perate zone, nor to the localities in the torrid, where climate and tem- 
perature readily make yellow fever and cholera endemic. Strange as it 
may seem, there are still partisans who have their objections, upon the 
blind belief that there is a mysterious, intangible principle in the propa- 
gation of epidemics, and so deny the benefits of preventive measures. 
The question naturally arises, in how far sequestration is advisable 
against exotic contagious diseases. 
i. This sequestration is only advisable in localities where a general 
supervision of the arrival of such diseases is easily made, and which are 
separated, so to speak, by a natural zone of isolation from suspected dis- 
tricts. Such are localities on islands or cities, where the entrance of the 
disease would be almost wholly by sea. In such places the necessary 
regime is easy of application. This is shown by the almost total immunity 
which this city enjoys from yellow fever, for not a season passes, but nu- 
merous cases are taken off of vessels and detained in the quarantine hospi- 
tal. During the cholera of 1865, many islands of the Mediterranean en- 
joyed an entire immunity from the disease. On the other hand, where 
topographical conditions are less favorable, this isolation from contagious 
diseases is almost impossible, and consequently it is illogical to impose 
such conditions upon them. 
Still another series of conditions would modify the application of these 
measures. Such are countries situate in the endemic zone of the disease 
which it is desired to restrain. Before deciding, then, upon its application 
for any given locality, we must determine whether it does not already ex- 
ist there; it may be in complete evolution, or as a localized germ. To 
apply restrictive measures without first determining these facts, is to es- 
tablish useless barriers, and renew under another'form one of the princi- 
pal abuses of the old system. The limits of this zone of endemicity are 
often difficult to decide, still a solution so far as yellow fever is concerned 
has been reached. The establishment of quarantines along our southern 
seaboard has shown that its endemicity scarcely reaches our shores : in 
other words, that, with the exception of a small portion of our southern 15 
coast, the disease is exotic. Still another set of conditions neutralizes the 
benefit of restrictive measures ? Certain countries are too distant from 
the seats of pestilence, or enjoy climatic conditions so peculiar, that 
these affections rarely find a lodgment. Take, for example, England : 
for the past two centuries her ports, relatively to the other ports of Europe, 
offer a remarkable immunity, when we take into account the extent of her 
commercial relations, against pestilential diseases. Shall we, then, say 
that the system of free pratique, which prevails in England, should be 
employed on the Continent ? Her immunity from yellow fever is the 
natural condition of her climate : this, while severe on the coasts of Spain 
and Portugal, is naturally mitigated as we ascend the Atlantic coast, until 
in England it finds a temperature wholly unsuited to its development. 
The same argument applies to the cities farther north than this on. this 
coast. Again, yellow fever seems to require a certain density of popula- 
tion, seldom appearing in places where the population falls much below 
five thousand. It is readily seen that few of these objections to the es- 
tablishment of quarantine observations apply to the cities of the Atlantic 
coast. Situate in the exotic zone, we know how useful restrictive measures 
have been during this century, in suppressing contagions almost entirely 
from the centres of population. True, much of this has been done in 
disregard of all consideration for the persons, the cargoes, or the vessels 
sequestrated, and been the occasion of bitter conflicts between the sani- 
tary and commercial interests ; but, since a better appreciation of the ori- 
gin and progress of p'estilential disease has been determined, it seems 
such interests are in no manner antagonistic, but, rather, that the pros- 
perity of commercial interests is inseparably connected with a healthy 
condition of the port, and that this can be maintained without contraven- 
ing their interest or prosperity. 
Shall we, then, in the presence of such marked differences, arising 
from topographical conditions, proclaim the complete inutility of quaran- 
tines, even in localities in which, at the moment of danger, every avenue 
cannot be guarded ? The transmission of epidemics through channels of 
human communications is too capricious to guard every avenue and man- 
ner of contact. All know, however, the special susceptibility of seaports, 
the guarding of which should be one of the principal preoccupations of 
the sanitary authorities in time of epidemic. If we cannot absolutely stop 
every method of penetration, we diminish, to a great degree, the chances, 
and preserve intact our commercial centre. 
The port of New York, regarded in this aspect, presents peculiarities 
which require a moment’s consideration, not with reference to her posi- 
tion to the yellow-fever zone, from which, since the use of steam-transit, 
the passage is made within the period of incubation of that disease, and 
where, without a supervising control, the infection is liable, during cer- 
tain months of the year, to be brought into the city, but rather to the 
peculiar feature presented by the emigration to this port. Nearly four 
undred thousand persons, cabin and steerage, enter annually, not from a 16 
single port, or the inhabitants of a particular nationality, but from every 
country, and every principal seaport of Europe. It is thus in an especial 
manner liable to the incursion of epidemics raging in any portion of Eu- 
rope, and experience has shown that their influence is carried hither, even 
easier than to England. A large emigration of Poles, Finns, and Walla- 
chians, is taking place, and, as they come from the direct neighborhood 
where cholera enters Europe, and where it has been more or less epidemic 
for the past five years, it imposes a constant vigilance upon the sanitary 
condition of those coming from such countries. These emigrants are 
lacking, too, in even the ordinary habits of cleanliness which characterize 
those from the more western portions of Europe; wearing whole suits of 
leather, it may be for months in succession, the clothing becomes in an 
especial manner easily contaminated, and, when so, impossible to purify. 
The limits of a paper will not permit a recital of the practices which gov- 
ern the inspection of these vessels, for it covers not only the prophylactic 
measures involved in the principle of quarantine, but also the general 
hygienic regulations which pertain to the comfort and well-being of the 
steerage-passengers. Indeed, the functions of the department are now 
extended to every thing which pertains to their hygienic condition ; so 
that, while the community, on the one hand, is protected, the passengers 
are maintained as cleanly as the crowded quarters permit, and a system 
of aeration and a frequent sending on deck is enforced. 
It may be asked, “ Are not the ports from which these emigrants sail 
equally exposed as this port? ” We answer, Decidedly not; they seldom 
receive from sea any of the passengers which they send to us under such 
crowded conditions. The emigrants reach those ports in small parties, by 
rail or otherwise, and it is only when a thousand to fifteen hundred are 
crowded in a limited space that the germs of contagious disease spread 
with such fearful violence. On land a single case may be promptly 
isolated; not so, however, on shipboard. Isolation and sequestration are 
almost impossible, while all concomitant influences, such as confined air, 
filth, bilge-water, and dirty clothing, are so many fostering influences for 
the germ. 
If the general principles we have expressed are correct, it will not be 
difficult to make the particular application, not only to any given locality, 
but also with reference to the particular disease it is desired to contravene. 
Such application must be founded upon the natural history, the man- 
ner of transmission, and the period of incubation of the disease, and, in 
shaping restrictive measures, all incidental circumstances must be borne 
in mind. Whenever rational hygienic measures are faithfully pursued, 
not only at the source of the infection, but also on vessels in transit, it 
should be a powerful modifying element, in the restrictions applied to 
passengers, cargo, or vessel, on their arrival in port. 
I have, however, so far transgressed your patience that I leave the 
subject, hoping, if agreeable to you, that I may, at some future time, elu- 
cidate this branch of the study. ON THE TRANSMISSIBILITY 
OF 
YELLOW FEVER AND CHOLERA 
IN THEIB 
RELATIONS TO QUARANTINE. 
BY 
S. OAKLEY VANDERPOEL, M. D., 
HEALTH OFFICES OF THE FOBT OF NEW YORK. ON THE TRANSMISSIBILITY OF YELLOW FEVER AND 
CHOLERA IN THEIR RELATIONS TO QUARANTINE. 
After the pretty full discussion of the principles which control the 
organization of quarantines, we can now advance to the study of the two 
principal diseases whose inroads they are expected to interrupt. The 
study will, of course, be limited to their origin and modes of trans- 
mission, and not in any way to their diagnosis, pathology, and treatment; 
the intent being that, by understanding the material features, an intelli- 
gent prophylactic course can be adopted. In the limited time allotted, 
this examination will be necessarily brief and cursory, and I shall there- 
fore only attempt to present the salient points in yellow fever and cholera. 
Yellow fever is a transmissible disease, its place of origin being, prob- 
ably, certain of the West India islands and portions of the shores of the 
Gulf of Mexico. Its prominent characteristics are—a feeble condition, 
vomiting of black matters, haemorrhages, and a yellow coloration of the 
skin, more or less constant, but which is usually most marked after death. 
The enumeration of symptoms indicates, at first sight, a general disease— 
an intoxication produced by a specific principle—which extends its action 
to the whole economy. It does not always present the same intensity. 
While usually assuming the severe form, we may have also merely outline 
or typical cases, which, to the sanitarian, are as much to be dreaded as the 
more decided. These half-sick often deceive the most rigid scrutiny; yet 
they possess the same specific element as the graver kind, and, in point of 
contagion, the same danger. Quite as much as the lighter forms of scar- 
let fever or small-pox convey the specific germ, so do these outlined cases 
of yellow fever. 
It is not necessary, in this connection, to enumerate the epidemics of 
yellow fever, even along the different cities of the Atlantic coast. It has 
appeared as far north as Boston, nearly two hundred years since, followed 
by several outbreaks during the latter part of the eighteenth century; 
while, in New York, during the last century and the early years of the 
YELLOW FEVER. 20 
present, it was marked by several epidemic appearances. It has become 
a yearly visitor at the port—not a summer passing but from twenty to 
sixty cases are treated at the quarantine hospitals. 
Yellow fever can, so far as the greater part of the shores of the United 
States are concerned, be termed an exotic disease. When and where are 
the precise spots of its origin will probably never be known. It is never 
shown on our shores except by importation. Once introduced, it may de- 
velop and propagate, but never spontaneously. Limited as seems origi- 
nally to have been the extent of territory from which it could claim origin, 
that territory has, through human intercourse, been very greatly extended; 
and there are now few places in the tropical and semi-tropical coasts of 
the Atlantic but what may be termed starting-points for the spread of the 
pestilence. 
In this connection it should be noted that, while the disease has been 
known on the Atlantic coast for over two centuries, it is only within the 
past thirty years, or thereabouts, that its appearance has been established 
on the coast of the Pacific. This, in part, may be accounted for by the 
difficulty of transmitting it, even in the hold of the ship, around the cold 
and wintry climate of Cape Horn; but also by another principle, scarcely 
less potent—the difference in the telluric aspect of the two coasts, the one 
offering conditions for a permanent nidus, the other wholly different. 
Much of the tropical and semi-tropical coast on the eastern shore of the 
continent is low, flat—through which large rivers pass slowly and sinuously 
—and is eminently unhealthy. The western slope, formed through most 
of its extent by the chain of Cordilleras, presents a far less favorable field 
for development. 
The special sources from which the fever emanates are those marked 
by paludal conditions. An alluvial soil, scooped or argillaceous; inun- 
dated, periodically, by long rains; covered or bordered by mangroves; 
channels with mixed salt and fresh water; pools of brackish water, or 
lagoons, formed at the mouth of the tortuous, sluggish river; these, and 
other paludal conditions—such as exuberance of decaying vegetation, 
subsoil infiltration—mark the immediate spots from which the fever may 
propagate. Yet, even here, let me recall a remark made when speaking 
on the general subject of malaria: that, with its paludal origin, it is not 
necessary to suppose that there is an identity of cause between yellow 
fever and the forms of malarial disease. The two diseases have been re- 
peatedly shown to exist simultaneously. The one is transmissible—the 
other is not; and, again, many countries, many localities exist which gen- 
erate a deadly paludal but no yellow fever. We may say that the germ 
of yellow fever appears to be of an organic, miasmatic nature—whether 
vegetable or animal cannot be affirmed—coming from endemic local- 
ities. These localities are exclusively found either on the borders of the 
sea or at the mouths of rivers, often in common with paludal fevers 
proper, but still differing from the latter in power of transportation for 21 
great distances, and preserving for a long time, without alteration, its re- 
productive germ. 
Recognizing, then, the telluric influence in the origin of yellow fever, 
there are certain local conditions which favor its propagation when trans- 
planted. First, its ravages are chiefly confined to low countries. Dr. 
Tower, after a careful analysis of all the localities in which it has pre- 
vailed in this country, finds none as high as five hundred feet above tide- 
water. Again, density of population is another element; it seldom as- 
suming an epidemic form in localities containing less than five thousand 
inhabitants. Humidity of the soil also exercises an influence. Soil sat- 
urated with water will preserve the disease-germ. In this respect it pre- 
sents a notable analogy to cholera. As with cholera, too, the social and 
hygienic conditions of a people exercise a notable influence in its propa- 
gation. It attains its greatest malignity among the filthy and impoverished, 
particularly if, as generally occurs, these reside in the low and ill-drained 
localities of any city. 
A word should be said relative to the acclimation of individuals. The 
general impression is, that the residents of tropical latitudes are, to a great 
degree, exempt, its ravages being confined to strangers or those unaccli- 
mated. This is, however, the case only when the disease is endemic. Let 
it appear for the first time in any tropical regions, and natives are quite as 
liable to fall its victims as any other class. Acclimation, therefore, is only 
to those who have passed a preceding epidemic period, without having left 
the country, and who must have been more or less impregnated with the 
yellow-fever germ. 
As the germ of yellow fever is, of necessity, transported from locality 
to locality chiefly by vessels, either engaged in commerce or war, it be- 
comes, to the sanitarian, a question of the first importance to determine 
whether the fever can develop spontaneously upon the ship. If its sponta- 
neity is possible, then sanitary measures and precautions should not be re- 
stricted to vessels coming from ports where the fever is known to exist, 
but to every vessel, in bad hygienic condition, traversing tropical regions. 
The opinion of physicians of extended experience is unanimous against 
the hypothesis of spontaneous generation. If it were possible, how is it 
that it never appears in vessels from China or India—vessels which, from 
the length of the voyage, and the long exposure to tropical heats, would 
seem to be in external conditions to favor the development ? 
While, therefore, the vessel may not create the specific cause, it may 
become a powerful agent for the concentration of the poison, independent, 
indeed, of the crew themselves. This power resides in the interior arrange- 
ments, in the stowage of the hold, in the material and character of the cargo. 
We frequently see, on shipboard, the disease reappear if it has ceased, 
or become exasperated if already present, should some change be effected 
in the stowage, no matter in what part of the ship this occurs. This per- 
sistence of infectious causes on shipboard is so remarkable, that some- 22 
times, after the unloading of the cargo, even for months, if the vessel is not 
thoroughly purified, every one entering the vessel is at once taken sick. 
While practically this cleansing on board of vessels engaged purely in com- 
mercial pursuits is easily and promptly effected, it becomes a very serious 
problem upon vessels-of-war. The more intricate construction of the latter, 
the difficulty of reaching the innermost parts of the vessels, render thorough 
purification almost impossible. Dr. Bell, of Brooklyn, for some years a 
medical officer in the Navy, has informed me that some of our vessels-of- 
war, once infected, could never enter a tropical region, no matter whether 
the disease existed at the particular point or not, but that the fever would 
reappear on the vessel; that, too, although the vessel in the mean time had 
spent a year in cold latitudes, without showing the least suspicion that the 
fever-germs lurked on board. It is this tenacity of the poison to the ship, 
which induced the hypothesis of spontaneous generation. It would rather 
be a powerful consideration that there was a living, vital germ, of remark- 
able tenacity whenever a favorite nidus for lodgment was presented. It 
becomes magazined in the hold and sides of the vessels. 
While to certain ports on this continent the question of transmission of 
yellow fever might, with some show of probability, be questioned, yet, 
when we have innumerable well-authenticated and observed instances of 
its transmission to European ports, and many of the more northern on 
this continent, it would seem that point required no extended discussion, 
and it remains only for us to determine the modes and manner of the 
transmission. 
Probably, in the literature of yellow fever, the features of no one epi- 
demic have been more carefully studied, and the surrounding circum- 
stances more carefully noted, than in that which occurred in St.-Nazaire, 
France, in 1861. Situate entirely beyond the yellow-fever zone, in 40° 
of north latitude, there was no danger of confounding the disease, or 
mistaking the modes of transmission. Every circumstance was most care- 
fully noted from the very inception of the epidemic, by an expert commis- 
sioner, on the part of the Government. In the statements now made, 
therefore, many will be drawn from the study of that epidemic, without 
necessary allusion each time to the source. I may state that experience at 
this port, and all the other writings I have consulted, fully corroborate 
the statements advanced. 
We have seen that the germ of yellow fever, having its initial point on 
the borders of the sea, or at the mouths of maritime rivers, in a compara- 
tively restricted part of the equatorial regions, may leave these regions; 
during transit it may be its presence is manifested, by the appearance of 
sickness among the crew; then, on the arrival of the vessel, we see, during 
and after its discharge, a series of accidents, which, starting from a com- 
mon source, go on to multiply, forming thus the starting-point of the many 
epidemics of yellow fever. We must now examine closer into the mode of 
this transmission, to determine whether the vessel, the cargo, or the crew 
and passengers are the agents. HOFFMAN ISLAND 
DIX ISLAND HOSPITAL. 
STATEN ISLAND IN THE DISTANCE. 23 
In the vessel the preponderating influence belongs to the hold; there 
is a confined atmosphere, in which the morbific germ goes on concentrat- 
ing, and which, when the hatchways are open, allows the disease to ap- 
pear, destroying those who come within its influence, even at distances of 
several rods. Those necessarily most exposed are the stevedores, who 
work in the hold, unloading the cargo, and the coopers who repair the 
broken packages. The water of the bilge is also a favorite lodgment for 
the germ. If, in the purification of a vessel, this is overlooked, the disease, 
if once present, will almost certainly reappear. Certain cargoes or articles 
will transmit the germ, but their influence is secondary to the hold of the 
ship itself, and are usually harmless unless the hold is already surcharged, 
so to speak, with poison. It may also be transported in the clothing of 
passengers and dunnage of sailors. It is not, however, directly contagious 
from person to person. In the five years that Dix Island has been used 
as a hospital for this disease, not a case has ever appeared among the at- 
tendants, or the residents of the island. Of course, precautionary means 
are taken, the details of which will be given when we speak of prophylac- 
tic measures. In this respect it stands in striking contrast to cholera. 
The one is transmitted by influences entirely outside the individual him- 
self, the other by influences arising directly from the person affected. To 
apply botanical terms, the one is exogenous, the other endogenous. 
The pernicious influence is exerted not only upon those who are im- 
mersed in the infected atmosphere, but the poison may be carried by cur- 
rents of air for greater or lesser distances, and, if the exposure be suffi- 
ciently long, affects those thus subjected. It can be distinctly traced for 
over a thousand feet. 
Some practical points remain for us still to determine : i. The incu- 
bation—upon the decision of this must depend the length of quarantine 
observation. The result of many observations has fixed the duration 
between two and six days ; most ordinarily three or four days. 
Having considered the origin of yellow fever, the extent of territory 
in which it has been acclimated, the manner of its propagation, and the 
duration of incubation, we are prepared to consider the necessary pro- 
phylactic measures. 
i. Measures to be taken at the port at which the epidemic prevails. 
Directly, we have no control of measures to be applied there—indirectly, 
our influence is felt, for the facility afforded to those who employ proper 
precautions warrants them in following the suggestions given. 
As filth is the almost necessary nidus for this as well as all contagious 
germs, the utmost cleanliness on the part of the vessel, and the persons 
of the crew, should be enforced. While the vessel is in port the bilge 
should be pumped out daily, and often sea-water pumped in until the 
water pumped out is clear. After the men have finished their day’s work, 
have them take a bath and put on clean flannels, and do not allow them 
to lie upon the open deck ; wherever there is a poop-cabin, so much the 24 
better. If the bodies are cleaned, and clean flannel used, all the animal 
effluvia and sweat which remain on the surface are got rid of; these are 
found to be a nidus for the germ. Still one more measure experience has 
told is beneficial. It has been found that sailors, whose bowels are kept a 
little active while in port, are less liable to take the fever, and if they do 
the attack is less severe. 
2. Transit of the vessel to this port. The hatches are to be kept open 
and the hold freely ventilated, whenever the weather will permit. It is 
in confined air that the virulence of the poison is concentrated. The 
bilge-water should be daily changed. On arrival at port, the duration of 
the traverse is first noted. If no sickness has occurred, and the passage 
has occupied more than six days, the crews, after thoroughly airing their 
dunnage, and submitting it to fumigation, are discharged. It may be 
noted that the crews seldom take any part in unloading the vessel. 
Careful inspection of the cleanliness, as far as can be, is made by the 
inspecting physician. The hatches and all possible openings are kept 
open for twenty-four hours in the lower bay, so that the strong air which 
usually prevails there shall permeate every part; every thing is then 
closed tight, and fumigation, as thorough as can be, is made in all parts 
of the vessel. Arrived at the lighterage-station, the discharge is com- 
menced at the earliest moment; there is absolutely no quarantine of 
detention ; for, if there be fomites on board, the longer it is allowed to re- 
main in the hold and bilge, the more virulent it becomes: a little leaven 
leavens the whole lump. Here, so far as the cargo is concerned, fresh air is 
wholly relied on. The raising of the cargo on deck in the open bay, pass- 
ing it to the deck of an open lighter, where it lies several hours for free 
aeration, carrying it some miles across the bay to a warehouse, so diffuse 
any fomites, that, in the two summers’ experience I have had, not a case 
of sickness has arisen from this source, and that, too, on very many ves- 
sels bringing sickness into port. 
Fumigation is daily made upon the vessel during the unloading. This 
discharge of cargo is performed by stevedores, who remain at the lighter- 
age-station continuously, no one ever being allowed to go to the city for 
six days after he has labored upon a vessel. The same rule refers also to 
the coopers, for you will remember it was stated that the great danger 
consisted in going into the hold of an infected vessel during the time of 
her discharge. When the cargo is entirely removed, the sides, and every 
part accessible, are subjected to scrubbing with brooms and water, after 
which a more thorough disinfection and fumigation follow, and the vessel 
is at once furnished free pratique. She is thus actually returned to com- 
merce sooner than if permitted to go to dock and be subject to the usual 
process of unloading. There is, therefore, so far as yellow fever is con- 
cerned, no antagonism between commerce and quarantine. 
Should the vessel have sickness at the time of entering port, or have 
had sickness or death on the passage, the vessel proper takes the same 25 
course: the sick are at once taken off, and the crew or passengers, instead 
of being at once discharged, subjected to surveillance until a period of 
five or six days from the last case shall have transpired. 
The large use of steam transportation between this and yellow-fever 
ports modifies in some respects the foregoing regulations. 
Reaching, as they readily can, this port within the period of incuba- 
tion, I have established the rule that five days must elapse from their de- 
parture before any passengers or crew can leave ship. As this time is 
more patiently passed at sea than lying in the lower bay, the time of pas- 
sage is usually made to fill the entire period. While five days is not the 
limit of incubation, I must depend somewhat upon the doctrine of aver- 
ages ; that is, if, in a hundred persons, passengers and crew, no case of 
fever is developed during that time, taking into account the possibility 
that with some it may have been in incubation at the time of their going 
on board, I conceive there would not be one chance in five hundred for 
it to develop on the sixth day. Passengers, if no sickness have occurred, 
are at once allowed entry to the city* Should there have been sickness, 
the course already indicated would be followed out. The steamer is 
lightered and subjected to the same process of cleansing as in a sailing- 
vessel. It is readily understood that, with steamers, time is a far more 
important factor than with sailing-vessels. With an average arrival of 
five or six weekly from yellow-fever ports during the past summer, not 
one lost her sailing-day. Here certainly was no antagonism to commerce. 
That our visits of inspection were not fruitless, sixty-two cases of yellow 
fever were taken from forty or more different ships during the past sum- 
mer ; that the protective measures were efficient, is shown in that not a 
case reached the city or came above the Narrows. 
I must now pass to the consideration of the remaining exotic disease, 
viz., cholera. It was my intention to discuss the many features of inter- 
est which cluster around the study of this disease quite .fully but I am 
reminded, by the very short time which remains, that only a superficial 
notice can be given of my last lecture. In its historical features it pre- 
sents, taken in connection with the frequency of its later irruptions, an 
unusual interest, while various writers have attempted to show that 
cholera was recognized in the writings of Hippocrates, quoting, indeed, 
the passage from that writer which attempts to prove such recognition, 
but which points unmistakably to cholera-morbus, or, as termed by the 
French, cholera-nostras. True, between the two there is a symptomatic 
analogy which is not manifested in the clinical expression. The specific 
cause separates them; the same as between a violent indigestion provoked 
by indiscretion in food, and the phenomena determined by taking certain 
poisonous substances. There may be an apparent similitude, though no 
identity of cause. 
If, however, we turn to the most ancient of the Eastern manuscripts, 
we have unmistakable descriptions of the terrible malady. The intermit- tent character of its virulence can also be recognized from the time of the 
first appearance of Europeans in that portion of the world. It was this 
intermittent character which caused so many years to elapse before its 
specific recognition. Following down the lapse of years after its recogni- 
tion, its presence is, from time to time, signalized. Even during these 
three centuries, and while communication with Europe was constant, it 
maintained almost wholly its endemic character, being limited to the 
southeastern portion of the Eastern Hemisphere. Nor was it until 1817 
that it assumed its migratory character. From this time it presents the 
singular phenomenon of a disease suddenly changing its character, to 
emigrate from its birthplace and extend its ravages throughout the 
world—to be carried from the borders of the Ganges to the Elbe, and 
finally to reach the capitals of Europe in 1831, and this country in 1832. 
The terror it has inspired, the frightful mortality following in its train, 
the repetition of its invasions, the almost well-grounded fear that it may 
become acclimated, explain sufficiently the interest which attaches to its 
study, and the multiplicity of writings of which it has been the subject. 
By universal assent, and a conviction derived from its non-recognition by 
earlier European writers, by its description in the most ancient of those of 
the East, by the study of successive irruptions during the present century, 
its origin is referred to the valleys of the Ganges and the Brahmapootra Riv- 
ers. Nor is the locality of its endemicity probably very extended. It 
may be described as general in the province of Bengal, and especially the 
city of Calcutta ; with less intensity in the stations of Cawnpore and Alla- 
habad, and their environs. In other countries of India- which, in this 
respect, may be termed near, and in almost similar external conditions, it 
appears as epidemic, it may be yearly, as at Madras and places of Hindoo 
pilgrimage, or every four or five years in the provinces of Northwestern 
Hindostan. As in yellow fever, so in cholera, the exact nature of the 
particular circumstances which produce the choleraic germ has not been 
determined, nor why it should be found particularly in that valley. All 
the peculiarities, both from the formation of the river, and the habits of 
the populations on its banks, have been mentioned, but without receiving 
the accredit of dispassionate observers. We can only say, with probability, 
that it, too, like yellow fever, has a paludal origin, the mysterious germ of 
which, once introduced into the human system, may go on in the process 
of propagation, without any lessening of its contagiousness or virulence, 
even though it had traversed large portions of the earth’s area, and had 
passed through millions of human beings. 
Like yellow fever, its power of transmission has also been denied, 
and, when the epidemic ravages have spread over whole countries, general 
influences have been invoked to explain the ravages. With its more care- 
ful study, few, I think, will venture to deny, not only that it is transmis- 
sible, but also that it is contagious. In this, bear in mind the broad dis- 
tinction between cholera and yellow fever. The latter has been stated as 27 
not strictly contagious, but transmissible through the media of many sub- 
stances, and the confined air and bilge of vessels. The former is, how- 
ever, directly contagious from person to person, and may be conveyed 
wherever there are routes of human intercourse, whether by land or sea. 
It is now, and has been for some time past, a favorite study to trace out 
the grand routes of the various epidemics which have, within the past 
forty years, so often scourged Europe and portions of this continent. We 
need here only refer to the results of those studies which have enunci- 
ated the principle of its transmission by the great routes of human travel. 
This is, then, the central fact of the study, that it is transmissible and 
contagious from the sick to the healthy, not by contact with the bodies 
of the sick, but with a material poison thrown off from their bodies, and 
capable of being conveyed to a distance. This recognized, we start from 
a presentable stand-point, and feel an assurance in efforts to prevent the 
spread of the pestilence. 
The question has often been raised, “ Why is cholera only an occa- 
sional visitant beyond the limits of its endemic house in certain prov- 
inces of Bengal ? ” It has been supposed that some unknown atmos- 
pheric conditions favor the extension of the disease at certain seasons, 
and not at others. True, as a rule, it is favored by high temperature, 
and checked by cold. Still there have been serious local outbreaks 
during the winter-season, in India, Europe, and this country. Neither 
great moisture nor extreme dryness of air is essential for the preva- 
lence of the disease, which has been widely diffused, and very virulent 
under the opposite extremes of moisture and of dryness. The disease 
has sometimes been known to break out with sudden violence after the 
occurrence of a mist-laden or a dust-laden wind blowing from a neigh- 
boring infected district, and it has sometimes received a sudden check 
after the occurrence of a violent storm. Probably human occurrences 
explain partially this remittent character rather than the influences of 
telluric or physical agencies. (In studying the habits of the people it is 
found the outbreaks occur coincidently with certain great fairs and pil- 
grimages, when immense multitudes are brought in close relation, with all 
the accompaniments of filth, and utter lack of all sanitary precautions.) 
The cholera shows itself every year, with more or less intensity, in an 
epidemic form in places where the pilgrims gather. Many of these com- 
bine both fairs and religious ceremonies. Among the principal places 
where this double purpose is carried out are Hurdwar and Jugger- 
naut (and Conjeveram). Hurdwar is in the north of Hindostan, on the 
Ganges, just where the river breaks through the mountains. The fair is 
held there every year just at the full moon of April, and every twelve 
years the pilgrimage is reputed more efficacious than ordinarily, and con- 
sequently the affluence there at such times is enormous. A million of 
persons from every direction are gathered there to make their ablutions 
in the sacred waters. Passing the night upon the banks of the river, 28 
without any covering, they strive to enter the water as nearly as possible 
at the same time. Scarcely do the ceremonies commence than the disease 
breaks out, and twenty thousand have been known to die in eight days. 
Can we seek for a more efficacious mode of distribution ? These pilgrims 
are not alone confined to Hindostan; but, over all countries where the 
Hindoo worship prevails, pilgrims come to these sacred shrines. They dis- 
perse to the northwest along the great caravan routes, carrying the pesti- 
lence in their train. A similar mode of distribution is recognized in the 
immense pilgrimages of Mohammedans to the sacred shrine of their 
prophet. 
While, therefore, recognizing the original spot and district from which 
cholera may radiate in an epidemic form, as also the means through which 
this distribution has been chiefly made, the question naturally arises 
whether or no it may become temporarily endemic or acclimated in any 
district. The inquiry at this juncture becomes the more pertinent, since 
thus far the most diligent research has failed to trace the epidemic of the 
past season in the Mississippi Valley to importation, and the chief medi- 
cal officers of Russia have made a similar declaration with reference to 
the severe epidemic in portions of that empire during the last summer. 
THE ACCLIMATION OF DISEASE. 
The solution of this question becomes of the highest interest, when 
we consider the important bearing it has with reference to the origin and 
portability of several cholera epidemics. 
The first point of observation is, that neither yellow fever nor cholera 
becomes acclimated in every point, where for a season they may prevail 
epidemically. Yet, wherever they occur in a zone where the meteorologi- 
cal conditions and physical formation of the soil resemble their original 
starting-point, it is not improbable the germs may remain for periods 
latent, to reappear in activity under some special conditions, the precise 
nature of which we are not as yet cognizant cf. The facts illustrative of 
this, derived from yellow fever, are numerous and well established : those 
of cholera bearing upon it are now undergoing lively discussion by epide- 
mologists, both in Europe and this country. It is generally conceded that 
the starting-point, the nidus of country, so to speak, from which both dis- 
eases sprang, is comparatively limited ; and yet we notice in the case of 
yellow fever that it is permanently endemic, in a large portion of the tropi- 
cal and sub-tropical regions of the Atlantic coast. 
It seems strange to tell you that yellow fever is older at all the north- 
ern ports of this coast than at New Orleans. Its first appearence in that 
city was in 1796, since which it has prevailed epidemically there thirty-five 
times, while not a season passes in which it is not more or less endemic. 
It appeared in Boston a hundred years'previous to that date, nearly the 
same in New York and Philadelphia, and in Charleston ten times before 
its appearance in New Orleans. This seems the more remarkable, that, 29 
while it was so frequently epidemic upon all the chief cities of the Atlan- 
tic seaboard, New Orleans was more closely connected in geographical 
position, commercial intercourse, language, and government with both 
insular and Central America, where yellow fever had prevailed for cen- 
turies. Several other places in that zone could be specified, where similar 
conditions are shown to exist: so much so, that we cannot always lo- 
cate the precise point from which an epidemic may spread. It is difficult 
to assert the same with reference to cholera. Its appearance is relatively 
far more recent; its birthplace so restricted, its usual course through the 
medium of pilgrims so apparent, that epidemologists have become accus- 
tomed to that source, and that alone, for the origin of every epidemic; 
and yet within the past year epidemics quite wide-spread have appeared, 
both in Russia and in this country, where the most diligent inquiry thus 
far has failed to trace the direct importation of the disease; and how 
would it be strange or strained if the analogy of yellow fever were applied 
to cholera ? Both diseases have a paludal origin, both are transported by 
what we must term, in our present state of knowledge, a germ, for the 
transmissible principle in both shows so many of the properties of animal 
and vegetable germs, we can relate it in no other connection. Now, all 
analogous forms of life readily propagate themselves whenever a suitable 
nidus is presented, even far from their primitive origin, flourish for a 
season, pass into a period of quiescence, to reappear again after a season 
in all their first activity. The period of this dormant vitality is not 
known, and is it difficult to conceive of cholera what is now fully recog- 
nized of yellow fever ? In the late cholera epidemic in Russia there was 
an interval of two years, 1867 to 1869, when it would seem to have been 
latent, and to have reappeared without the importation of any new germ; 
and Dr. Blikan, as Director of the Medical Department of the Russian 
Government, says of the epidemic of the last season, that, “ the infected 
localities being separated from each other by an immense space, entirely 
free from cholera, the idea of any genetic connection between the epi- 
demics which visited these localities, falls of itself to the ground.” 
You are all aware of the wide-spread epidemic which has prevailed 
during the past summer in the Mississippi Valley. Starting in April in 
New Orleans, it pursued its usual course of propagation to all the princi- 
pal towns along that river, varying in intensity in almost every instance 
with the cleanliness of the place, and the vigor of the local hygienic 
measures adopted to suppress it. Now, the most diligent, painstaking re- 
search has so far failed to trace it to importation. The heretofore recog- 
nized necessity for such an introduction left no stone unturned to establish 
it in this instance. The local sanitary authQrities of that city, early im- 
pressed with the necessity of deciding the inquiry, have failed to find 
even the most distant trace of importation. The chairman of the State 
Board of Health of Louisiana gave the subject his earnest and prolonged 
research; the physician to the lazaretto at New Orleans affirms that he 30 
examined every vessel bringing passengers from European ports during 
the months of January, February, and March, that not a death occurred 
upon the passage, and not a case of diarrhoea was noticed.- So far the 
universal negative testimony, of those whose duty would be to know, is 
entirely opposed to importation, and we are compelled to accept their re- 
port until a positive relation can be established. I might add incident- 
ally, that many of the telluric and meteorological conditions of the lower 
Mississippi resemble the Ganges, and that it would be difficult at least to 
suppose that the same dormant condition of the germ known to exist at 
the Ganges may occur at the delta of the Mississippi. If cholera be 
propagated by a germ, would there be a radical difference between that 
and all other germs. And yet, who has ever supposed that the germ, in- 
fection, or whatever it is called, of small-pox, became any the less active, 
much less lost its vitality, because it did not always prevail in an epidemic 
form; or, again, who ever failed to see the characteristic pustule of the 
vaccine, even though it had passed through hundreds since its renewal ? 
You readily see, gentlemen, the solution of this question has an important 
practical bearing. If the doctrine of even y«arz-acclimation be accepted, 
we must look even more closely than we have done heretofore to the ful- 
fillment of all local hygienic measures. 
Do not misapprehend me; this is no effort to show that cholera may 
spring de novo, wherever the external conditions of fomites and filth are 
favorable to its development; it recognizes the vital, living germ—the germ 
which, when active, produces cholera and nothing else; still a germ which, 
when#it has found its appropriate nidus, may remain for a season quiescent, 
until seasons and conditions conspire to have it display its full power as an 
epidemic. 
Perhaps it may be suggested here that the acclimation of yellow fever 
is admitted, but not so with regard to cholera, since the germ of each is 
transmissible in different ways. The germ of yellow fever not being gen- 
erated in the human system, nor transmitted from person to person in any 
way, but generated outside, and taken up after the manner of marsh-ma- 
laria, easily finds its acclimation in the many articles in which it is trans- 
ported, but that cholera-germ, generated in the individual, could only be 
transmissible by the actual presence of those suffering from it. This, it 
seems to me, is the strongest point of the argument against acclimation. 
Yet who will decide the length of time during which the cholera-germ may 
retain, vitality when in a favorable nidus ? Who will determine the length 
of time that the trichinse or the tape-worm may continue in the cestoid 
state unless favorable influences for their development occur ? The little 
animalcules which swarm each mud-pool are, as the pool dries up, carried 
off with the floating wind, to reappear in full activity at the next summer’s 
shower. The epidemic in Russia has shown that the germ remained vital- 
ized for two years at least; how long would this continue under the more 
favorable influence of a tropical clime ? 31 
Dr. Macnamara states that if fresh cholera dejecta are dried on clothes 
and furniture, or in the soil, they retain their activity for years, if access 
of moisture be prevented. He had some of the dejecta which when fresh 
were mixed with sand and dried seven years before. Now, when mixed 
with water, and exposed to the sun, they could not be distinguished from 
a fresh cholera-stool. 
Having established that cholera can be transmitted, it remains to show 
how this occurs, what are the agents of transmission, how it is influenced 
by the different modes of locomotion, the crowding of persons, what are 
the attributes of the generating principle, the means by which it enters the 
organism. In the limited time remaining, these can be treated only in the 
most general manner: 
1. This contagion always follows the routes of travel, and never pro- 
gresses faster than it can be transported by an individual himself. In this 
is of course included all that pertains to his progress; his baggage, mer- 
chandise, the vessel which carries him, every thing indeed which accom- 
panies him. 
2. The poison of cholera is cast off with the characteristic discharges of 
the alimentary canal, and communicated to others in the following princi- 
pal ways: 
1. By the soiled hands of the attendants who are not careful to wash 
before taking their food. 
2. By means of bed and body linen, carpets and other articles soiled 
by the choleraic discharges. 
3. The discharges finding their way into the sewers and into the soil 
may spread the disease in various ways : 1. By percolating through the 
soil into wells and other reservoirs of drinking-water. 2. By rising with 
watery vapor into the air. 3. By becoming dried, and then dispersed 
with the atmosphere in form of an impalpable dust; or, in the words of 
Mr. Sirnon, Registrar-General of England, “ it cannot be too distinctly 
understood that the person who contracts cholera in this country is, ipse 
facto, demonstrated with almost almost absolute certainty to have been ex- 
posed to excremental pollution—excrement-sodden earth—excrement- 
reeking air—excrement-tainted water. ” 
Nor is it essential for this contamination that the infected person 
should be laboring under the full access of cholera-symptoms. The affec- 
tion is just as certainly transmitted, and probably more frequently, by 
persons suffering from mere choleraic diarrhoea. The essential germ is the 
same in both, and the choleraic diarrhoea of one will develop into the ma- 
lignant form in another. Whenever it passes by a sudden leap from ah 
affected locality to one not as yet poisoned, it is probably by some such 
transportation. Persons so affected are' moving about, it may be traveling 
in cars or on river steamboats. Each dejection, miles separate, may dis- 
seminate the poison in the particular locality. Numerous authenticated 
cases are on record of propagation in this manner, and, during the epi- 32 
demic of the past summer in the Mississippi Valley, its capricious mean- 
derings were many times traced by this mode of transmission. Its impor- 
tation to this country is of necessity by ships, and, as by far the greater 
portion of people enter this port, the danger from this source is relatively 
greater here than in any other. To show the activity it acquires after 
being retained for a time on board, let me recite the following fact; The 
steamship England arrived off Halifax a few years since with chalera on 
board. A pilot, with an assistant and his son, went off to the ship in an 
open boat. Hearing that there was sickness on board, the men remained 
in the boat, which was towed at a considerable distance astern by a ten- 
fathom line. In this way the ship with the boat in tow was conducted 
to her place of anchor. The pilots then went on shore, and were never 
on board the infected ship. In the course of the next two days both men 
were seized with cholera, and one died. Both men communicated the dis- 
ease to their families. In the family of one there were three cases, but no 
death; in that of the other,besides the father who died, there were four 
cases, and two deaths. The only other cases of cholera in Halifax at that 
time occurred in the family of a man, whose two children were seized, after 
playing with soiled bedding which had floated on shore from the infected 
steamer; one child died, the other recovered. The mother also took the 
disease and died. Surely if disease was ever communicated by infection, 
it was so in the case of these three families, the different members of which 
were in various ways brought into contact with the infecting material im- 
ported by the steamer. 
An indirect proof of the contagiousness of cholera is afforded by the 
fact that the disease has never reached certain countries which, being 
separated from India by a wide expanse of ocean, and having little com- 
munication with that country, have escaped the infection. Among the 
countries are Australia, New Zealand, and the other Pacific islands; the 
Cape of Good Hope, and the southern part of the west coast of Africa; the 
Azores, Bermuda, Iceland, thq Faroe, Orkney, and Shetland islands, and 
the western coast of South America. 
Of the agents for the immediate transmission of cholera, impure water 
plays an important part. Whoever has kept pace with the many writings 
on cholera, will see the importance which of late years has been attrib- 
uted to impure water as an excitant of cholera. Not only on the general 
principle, that water rendered impure 'by the presence of large quantities 
of organic matter, favors the spread of an epidemic, but also from water 
contaminated directly by cholera excretion. Now that public attention is 
fully awakened to this matter, and also the fact that, almost for the first 
time in this country, the epidemic of the past summer was carefully noted 
in many places, we have many interesting proofs establishing this source 
of poisoning. In the first case which occurred in Lexington, Kentucky, 
the dejections were thrown out, so that by percolation they reached a well 
situate near by; twelve subsequent cases were clearly traced to this water 33 
contamination. In this connection, I can as advantageously notice as 
elsewhere, that out of a certain number of persons who are exposed to 
cholera contagion, whether by impure water, contact with excretions in any 
form, but a moderate percentage really suffer from such exposure: thus 
out of nineteen persons known to have drank inadvertently of water, in 
which cholera excretion had been thrown, but five suffered from the dis- 
ease. Observations show that in a crowded community, apparently equal- 
ly exposed to the same influences, the above figures are not far from the 
average, of those who will show actively the contamination. It happens, 
then, that a large majority of persons exposed to cholera-poison escape 
completely, or incompletely, though of the latter there are far more than 
of complete immunity. Of this category are the great number of choleraic 
diarrhoeas known to prevail at the time of an epidemic. This immunity 
may extend to entire communities, for, after the recent presence of an epi- 
demic, there is an indisposition for another, even though there may have 
been an entirely new importation; a condition somewhat similar to what 
we noticed in yellow fever—the community is for the time acclimated. 
Let me return, however. Another fruitful mode of contamination is 
from soiled clothing. Again and again has it been carried into perfectly 
healthy districts by sending into such localities clothing which had been 
soiled by those suffering from the disease. Those, too, who wash such 
clothing are peculiarly exposed ; indeed, it should be an established axiom 
that no contaminated clothing be washed until it has first been thoroughly 
immersed in some disinfecting fluid. Here, too, I may notice a clinical 
fact which is of practical value. There is good reason to believe that the 
fresh cholera-stools are nearly if not quite harmless; that their greatest 
infecting power coincides with the stage of commencing decomposition, 
and that in a more advanced stage of decomposition they again become 
harmless. The practical deduction is obvious : that attendants may, al- 
most with impunity, wait upon those affected if the dejections are immedi- 
ately thrown in some disinfecting composition, and care is taken to wash 
the hands and promptly remove soiled clothing. In addition to these 
direct modes of communication, the virus may be diffused through the 
air, and thus enter the system by the lungs. Its rapid dissemination in a 
locality attacked, the simultaneousness of a great number of cases in a 
given agglomeration of persons where contact has not been possible, the 
fact that persons may be attacked at a short distance from the suffering 
case, favor the proposition, and attest to the volatility of the cholera- 
germ. The distance to which the principle can be, in this way, trans- 
ported is probably limited, but still must be recognized in studying the 
active modes of propagation. 
Pettenkofer, who has given to the subject long and patient study, in- 
sists that soil-saturation performs also an important part in this propaga- 
tion ; i. e., that a porous soil, easily permeable to air and water, coin- 
ciding with an elevated water-level from subterranean springs, and espe- 34 
daily coinciding with changes in the level of these waters, becomes an 
active agent in disengaging the poison once brought to it. 
We have now no difficulty in understanding that cholera is a disease 
capable of being rapidly communicated from the sick to the.healthy over 
an extensive population, and yet that, with ordinary precautions, the 
immediate personal attendants on the sick incur scarcely any risk of 
infection. In this respect, there is a very close resemblance between 
cholera and typhoid or enteric fever. The alimentary canal is in both 
diseases the chief if not the sole outlet for the poison. The bowel-dis- 
charges are the means for the infection, and, whereas the fresh secretions 
are comparatively innocuous, the subsequent fermentation of the dis- 
charges from a single patient may infect the drains of an entire district. 
Hence, it follows that the inhabitants of a house with untrapped drains, 
half a mile or more away, may incur three times more risk of infection 
than the sick man’s nurse or doctor. 
Having established the proposition that cholera can be transported, 
and pointed out some of the principal modes by which it is transmitted, 
it remains, in order to complete the picture, to fix the duratioti of the incu- 
bation, for cholera, like all contagious diseases, requires a certain time 
after its introduction into the system to develop its specific character. 
The congress of 1865 at Constantinople discussed this point long and 
fully; for the fact that the period of incubation may be from a few hours 
to (as many asserted) several days, necessarily called forth the most varied 
opinions. It is probable some of this diversity would be reconciled if 
the choleraic diarrhoea, which so often precedes the more intense symp- 
toms, could be more rigidly determined. In the practical operations of 
the quarantine, we cannot, from its greater facility of transmission, take 
the average incubation, as in yellow fever, but rather extend it beyond 
the extreme period, say ten days. 
It now remains to deduce the preventive measures, based upon these 
views of its history and modes of transmission. Our remarks will apply 
only to those applicable to its ingress by way of the sea. First, then, no 
arbitrary rules can be laid down which shall be applicable to all vessels. 
Every arrival of a vessel with cholera must, having in view all the general 
laws we have laid down, be judged by the particular features which belong 
to that case. While, as a rule, every vessel, its passengers and crew hav- 
ing had cholera upon its passage, or at the time of its entry, should be sub- 
jected at least to a quarantine of observation, still this rule is not with- 
out exceptions. For instance, two steamers entered the harbor last fall, 
having had deaths from cholera, and another with one well marked, and 
several of choleraic diarrhoea on board, neither one of which was de- 
tained more than twenty-four hours; and yet 1 felt quite secure in allow- 
ing them to proceed to the city. Why was this ? In the first, the case 
was a cabin-passenger. The nature of the disease was almost immedi- 
ately detected by the surgeon. At once absolute isolation was enforced, passengers from neighboring state-rooms were removed, dejections disin- 
fected, and care taken with reference to soiled linen. Seven days had 
elapsed since the death; when the vessel entered, the state-room had been 
scrupulously cleaned and disinfected daily. Here, then, every intelligent 
preventive measure had been employed; the time of incubation, when 
any passenger having contracted the disease before entering the vessel, 
was past, and, in view of the measures employed, I had only to consider 
the possibility of contamination from the particular case. It had been 
limited to one; the average time of incubation was more than past 
since his death, without another case, and I therefore decided to let the 
vessel go up. Now, had a cast- iron rigidity been followed, without reference 
to the measures which the surgeon employed, all the passengers should 
have been taken from the ship, subjected for eight or ten days to a quar- 
antine of observation, the vessel itself thoroughly cleaned, and every part 
aired and daily fumigated. While such a course would have been war- 
ranted by law, and sanctioned, too, by sanitarians, I felt that the precau- 
tionary measures adopted were sufficient, and would encourage medical 
officers and the shipping interest to attack the disease at its source, rather 
than passively allow it to gain full headway, under the conviction that no 
efforts they might apply would be recognized by the sanitary authorities 
of the port. 
The other death was in the steerage, so sudden that the surgeon was 
not informed until actual collapse. On inquiry, no dejection had taken 
place except at the water-closet into the sea; none occurred after the col- 
lapse ; the clothing was at the time examined to see whether any stain 
was upon it; the body was at once thrown overboard, all the effects disin- 
fected, and ten days had elapsed since the death, on their arrival. 
Wherein would a quarantine of observation have helped me in this matter? 
In the case of cholera which entered the port, every precautionary 
measure had been adopted ; the most rigid examination and inquiry could 
not detect other cases of choleraic diarrhoea than those referred to. The 
period of incubation, from acquiring it before entering the ship, had 
passed, and, with no evidence of contamination to others, the vessel was 
allowed pratique. 
In acting in this manner in the above three instances, I but followed 
on a limited scale what is universally recognized by all the European gov- 
ernments,* and to which all their later efforts have principally tended, viz., 
to suppress the disease as far as possible at its source. They feel that the 
great field for precautionary measures is in the home of the disease, and 
the local governments are, as far as possible, discouraging the great pil- 
grimages, with the large agglomerations of people, and their subsequent 
religious rites, with already an appreciable diminution in the routes of 
transmission. 
A vessel arriving, however, with several cases on board would be com- 
pelled to undergo the full ordeal of precautionary measures. The pas- 36 
sengers would be removed from the vessel, subjected to a quarantine of 
observation, any sick appearing be promptly removed to the hospital 
located on another island, a mile distant from the island where the quar- 
antine of observation was enforced. In the mean time all clothing would 
be thoroughly washed, aired, and disinfected, and, when eight days had 
elapsed without the appearance of a new case, they would be allowed 
to leave. In the mean time the vessel, after being subjected to thorough 
cleansing and disinfection, would be allowed pratique. 
I think you will agree with me, gentlemen, that in the restrictive meas- 
ures there is no blind formalism, nor any mysterious proceedings. All are 
deducible from the accepted notions of the history, nature, and modes of 
transmission of the disease. If this principle is faithfully carried out, 
there will be, I am sure, no antagonism between sanitary and commercial 
interests, but most of the measures adopted in behalf of the one will indi- 
rectly promote the prosperity of the other.