ting, however, that this explanation is the true one, we still have remaining the fact that the germs contained in the clothing and boxes of these men, withstood the rigorous winter of 1878-9 first in Norfolk and afterwards in Boston. These facts would indicate that the poison of this fever has gained the power, by acclimatization or evolution, to withstand the action of a temperature which at one time was, or at least was supposed to be, fatal to it.

It would appear also, from some observations lately made, that the yellow fever poison possesses another peculiarity not before suspected; that is, that, when first emitted or discharged from the subject (whether from the skin, lungs, bowels, or urinary surfaces is as yet unknown), it is not in an active or potential condition, but must and does subsequently undergo a further development or growth, by which it does become active and capable of imparting the disease. This places the disease in that class which Liebermeister (incorrectly, we think) styles "miasmatic contagions," which includes enteric fever, cholera, and probably epidemic dysentery; and accounts satisfactorily for its apparently direct non-contagiousness.

The observations upon this point are as yet few, but seemingly very conclusive. Thus: The bark May Queen, Capt. Benjamin Springsteel, sailed from Rio Janeiro for Baltimore in January, 1878, with a clean bill of health. When three days out, two of the crew were attacked with yellow fever, one of whom died; the other recovered in a few days. About forty days after the death of this sailor, when about to enter the capes of Virginia, the weather being cool, three more of the crew were attacked with this fever almost simultaneously. Again: "In the year 1877 yellow fever prevailed as an epidemic at Fernandina, Florida. A gentleman having relatives in Augusta, Ga., moved with a portion of his family to that city to escape the disease.... The man himself was in a few days attacked with yellow fever, contracted in Fernandina, and died shortly afterwards with black vomit. Two large Saratoga trunks, containing the clothing of the father and daughter, were opened in the house shortly after their arrival, and just before the death of the former. Neither the daughter nor any member of the resident family was attacked with any disease for six weeks. At the end of this time the daughter, who opened the trunks, was attacked violently with yellow fever, and in rapid succession all the other

members of the family developed well marked but mild cases of the disease-which did not extend beyond the household of this family."

Only one more observation will be related in this connection. It seems as conclusive as those already given.

In 1878 the first cases of yellow fever occurring in the town of Chattanooga, Tenn., were a German woman and her child, who had fled from Memphis. Both died. A rigid quarantine was subsequently established, and no other cases occurred for a period of six weeks. Then the disease appeared, as I am informed, in the same hotel where the woman and child had died, and the health authorities were utterly unable to account for the outbreak.

This long interval between exposure and attack, cannot be accounted for by what is called incubation of the poison; for the period of incubation in this disease has been thoroughly established as being within two weeks. The fact can only be explained upon the hypothesis that the yellow fever germ, like that of the typhoid and some other fevers, is not capable of producing yellow fever when first emitted, but must and does undergo a certain development of growth afterwards, by which it acquires a malignant property not before possessed. It is the germ of the poison, but not the poison itself. And this satisfactorily accounts for the remarkable fact that this disease, so dreadful in its mortality; so generally prevailing as an epidemic; whose contagion spreads by infection, and can be transported from place to place as easily as a trunk or a bale of goods, is yet never personally contagious.

This would seem to be an important acquisition to our knowledge of the natural history of yellow fever; for it clearly explains many anomalous and hitherto inexplicable facts and incidents in the propagation and march of epidemics of this disease. But it is still more important in the power which this knowledge gives us, to control and arrest the spread and diffusion, as well as the growth and multiplication, of the poison. It tells us that upon the introduction of a case of the fever from abroad into a healthy community, we have an abundance of time to destroy the germ of the contagion, before other persons can be infected by it. And it also tells us that in such a case, while there is no

1 Transactions of the Medical Associatiom of Georgia, for 1879. Dr. Henry F. Campbell on "Yellow Fever Germ."

cause for an immediate panic, and all who can do so have ample time to place themselves beyond the reach of a possible epidemic without danger to those who give them refuge, there is also time enough in which to destroy the germs before they have acquired that malignant vitality or growth by which alone they can become deadly, and that, by destroying all the belongings of a yellow fever patient, and by thoroughly purifying and disinfecting him and all his surroundings, all danger of propagation can be absolutely prevented.

But I need not dilate upon this subject, since all the facts mentioned are now pretty thoroughly understood, and a commission of able and learned medical gentlemen have the matter under consideration, who will doubtless devise the best means. of applying our knowledge to the great end so dear to us all, of limiting the spread of epidemics and diminishing the general mortality. I therefore turn from this ghastly subject to another of far greater importance in my estimation, in the hope that I may arouse your attention and excite your efforts to diminish the ravages of some other diseases, which are silently destroying every year, an infinitely greater number of our race than yellow fever and cholera combined. These last only visit us at intervals of great or less length of time; but their destructive effects are so sudden and rapid, the fear and horror they excite are so great, that public attention is thoroughly aroused, and the heart of the nation throbs with pity and compassion, and the full hand of charity is ever ready to extend the means of alleviating the wants and comforting the sorrows of the pestilence-stricken community. But the silent hand of death, in the form of consumption, scarlatina, and diphtheria is annually laid upon thousands, whose departure produces no public excitement, whose deaths are only recorded in the weekly bulletins of the health office, and who leave no memorial behind them except in the stricken hearts and sable garments which meet us in every vehicle and thoroughfare of public travel.

The mortuary reports of the five principal Atlantic cities, Boston, New York, Brooklyn, Philadelphia, and Baltimore, reveal the fact that in the year 1879, 70,369 persons died; and of these cousumption caused the death of 11,872, or 16.8 per cent. of the whole number; scarlatina 2666, or 3.87 per cent.; and diphtheria 2357, or 3.36 per cent., making the total mortality from these three diseases 16,895, or 24 per cent. of the total

deaths in these five cities. An examination of the statistics of such other smaller cities and towns as furnish reliable reports, convinces me that the rate of mortality for the whole country will not vary materially from that of these cities. It is almost certain, therefore, that these three diseases alone, destroy more people every year in the United States, than have been killed by yellow fever and cholera in the last twenty-five years.

Two of these at least, diphtheria and scarlatina, are preventable diseases; while no one who has thoughtfully observed the class of people who furnish the largest contingent of deaths from consumption can doubt, that the mortality from this terrible disease might be very materially diminished by improved hygiene in dwellings, in clothing, in food, and in occupations. The last three of these are, perhaps, beyond our help or control; for there must and will be, as long as humanity is what it is, poor people, who, with scanty clothing and insufficient food, must follow occupations necessary to our civilization, which are essentially unwholesome. But the first of these conditions is, partially at least, under our control.

In every large city, and many small ones too-for these, without any good reason whatever, must follow the errors and ape the vices of their more pretentious sisters-are found numerous narrow streets or alleys, varying in width from ten to thirty feet, into which the sunlight never enters except for an hour or two each day. On these narrow, dark, and noisome streets are usually found small houses of ten to fifteen feet front, and two or three stories in height. Quite often every room of these illventilated dwellings is occupied by a family consisting of two to five or more persons. The air in these alleys is close, and heavy with the fetid vapors arising from decomposing garbage and other filth of every conceivable description. A small hillock of offal, of varying but generally of long accumulation, is often found in front of every house; for the street-cleaning brigade visits these purlieus only at rare intervals. The public thoroughfares of commerce and fashion are kept scrupulously clean, but these alleys are generally neglected, and cleaned only when the foul odors emanating from them are complained of by some influential neighbors.

Quite often, too, even in these narrow passages, as well as on wider and more pretentious thoroughfares, "basements" or underground apartments are found, either inhabited by one or

more very poor families, or occupied as kitchen, dining, and sitting room by others in better circumstances, and who ought to have better sense.

It is in these noisome alleys and damp basements that consumption, diphtheria, scarlatina, and rheumatism find their congenial homes; and here, too, the best efforts of physicians at successful treatment are baffled by the insanitary and deadly surroundings. No one can doubt the influence of bad air-I mean air deficient in oxygen, and diluted and poisoned with carbonic dioxide, sulphuretted and carburetted hydrogens-in causing and predisposing to those numerous nutritive derangements which tend to induce tuberculosis and catarrhal pneumonia. Can it be wondered at, then, that in cities where hundreds. of thousands of people live in dwellings such as I have described, so many thousands should die of consumption? In New York and Brooklyn alone, in the year 1879, 5990 persons died of this disease. Had yellow fever killed one-half this number a storm of indignation at the inefficiency or supineness of your health authorities would have arisen not only in your city, but all over the country, and you would have expended millions of dollars in stamping out the pestilence.

Now, while it is perhaps vain to hope that consumption, diphtheria, or scarlatina will ever be completely banished from the world, no one will deny that by removing the insanitary conditions I have mentioned, the number of cases of these diseases would be most materially diminished; while the mortality of the remaining cases would be correspondingly lessened.

Here, then, O my brothers, is a field in which all of us can labor for the good of our common humanity, and in which we can ultimately accomplish far more good than by a vain search after drugs with which we may idly hope to combat disease or repair the destruction it has wrought! Let us unitedly raise our voices so loudly, and proclaim our protests so often, against this fatal overcrowding of population, that even the deaf ears of the politician will hear us; and so, laws may be enacted. which will lay their restraining hands with iron force upon the greed of landlords, and save the people from the consequences of their own stolid ignorance. Even if we fail to eradicate present existing evils, we can hope, at least, to so educate public opinion, that their repetition will be impossible, and that in the building of new cities, as well as in the enlargement of old ones, VOL. XXXI.-11