young, the robust, the plethoric, and strangers are peculiarly subject; and these last are oftenest the victims of the disease. Both these forms of fever are most severe and fatal, as I think I remarked before, about the latter end of summer or the beginning of autumn; that is, in proportion to the number of persons affected: yet from the much wider prevalence of their milder grades in the variable weather of autumn, the absolute number of deaths will, upon the whole, sometimes be the greatest in this latter season; and hence it is, that, strictly speaking, when we have the most sickness, we have comparatively the least mortality!

I am not quite certain that I have ever seen the black vomit in any of our endemic fevers; but a vomiting of black matter of various descriptions is no unfrequent occurrence. In 1799, when we had a true yellow fever in Edenton, I saw the genuine black vomit in several cases; but I do not believe I have ever seen exactly the same thing since: though I confess I have seen perhaps half a dozen cases in which my suspicions have been strongly excited. Hemorrhages from the nose and gums are occasionally met with in protracted cases ending fatally; and I remember one case of a malignant nature, in which a bleeding from the mouth took place, that ended in death in three or four days. Glandular swellings, so far as my observation has extended, have not been among the characteristics of any of our fevers. In most of the fatal cases of inflammatory remitting fever which have fallen under my notice, the heat of the skin has continued intense until a short time before dissolution, and the patient has expired in a paroxysm or exacerbation of fever. The bilious remittent, when about

to prove mortal in a majority of instances, puts on the garb of typhus, and terminates with the symptoms common in the last stage of that disease.

I have thus, sir, given you an account of two forms of fever, as they appear in the tract of country to which my practice has been confined; and all the continued remitting, or what are usually denominated bilious fevers, incident to our climate, seem to me to be only modifications, or variations of these two original and distinct diseases. Neither the inflammatory nor the bilious remittent always attack and progress precisely as in the history I have sketched. They both vary in their modes of attack, in duration, in violence, in the remissions and exacerbations that attend them, and in many of their less essential symptoms. Nevertheless, I feel persuaded that, from the description I have given, the peculiar and distinguishing character of each will be sufficiently manifest. Very respectfully,

JA. NORCOM.

IV.

CONJECTURES, respecting the NATIVE CLIMATE of PESTILENCE; in a letter to the editors of the Medical and Philosophical Register. By an OBSERVER.*

THE frequent recurrence of a pestilential fever, in New-York and Philadelphia, since the year 1793, has

Communications from the learned and ingenious writer of this paper will always be acceptable, and are solicited by the editors.

D

become the subject of painful apprehension to many of our fellow-citizens. They deem it probable that the golden age of our seaport towns is past, and that we have entered upon the age of clay. The ills of life, that cannot be avoided, are confessedly very numerous; and there is not any reason why we should create imaginary evils. I do not call an apprehension of the yellow fever an imaginary evil; nor should we neglect all prudent and practicable means, by which the frequent recurrence of that disease may be prevented: but I deem it improper that we should afflict ourselves by supposing that our lots are cast in the very latitude of pestilence, and that our climate is now beginning to shew that one of the greatest scourges of humanity is its natural production.

It is alleged, as I presume, that we live in the latitude of pestilence, because the plague, which, like the yellow fever, is a pestilential disease, has long infested the western parts of Asia, from the thirtieth to the forty-second degree of north latitude. That conclusion, as I think, is not fairly drawn from the premises.

There are some diseases, as we know, that chiefly prevail in cold climates; and there are other diseases that are the natural productions of a warm climate. Diseases of this kind are produced by a long continuance of heat, or of moisture and heat, whereby the quality of animal and vegetable productions, suspended in the atmosphere, are essentially changed, so that they become hostile to the human constitution, and produce the most fatal complaints. The yellow fever and the plague are generally thought to be diseases of this class. remarkable circumstances in which those diseases resemble one another.

There are some

They both depend upon a certain degree of heat. The plague seldom spreads when the degree of heat is below sixty or above eighty degrees, in Farenheit's thermometer. The yellow fever seems to require a long continuance of heat at eighty degrees for its origin. It may be communicated at a lower degree, but it is effectually destroyed by frost.

Both of these diseases require, beside the degree of heat mentioned, a certain diseased constitution of the atmosphere towards their propagation. Neither of them is contagious in a pure atmosphere.

It does not follow from either of those circumstances, that any part of the globe, above the tropics, should be deemed the latitude of pestilence. The contrary, as I think, is clear; for no disease that is constantly destroyed by cold can be indigenous in a climate were such a degree of cold prevails every year. From this it must follow, that though the yellow fever may exist at all times within the tropics, it must be counted an exotic plant in the state of New-York.

Perhaps I shall be told that the plague, though it cannot endure a high degree of heat, such a degree as prevails every year in Egypt, yet it is the natural production of that country. I am aware that any objection to this opinion may be deemed paradoxical; yet I question whether a particular zone or broad belt of this globe, extending from the 29th to the 43d degree of latitude, can, with propriety, be called the latitude of pestilence. There was

a time when Egypt, that most unfortunate of kingdoms, was more populous than it is at present, and contained larger cities than Cairo; but it was not in that age the seat of pestilence. We should infer, from the rapid increase of the Israelites in that country, that the climate was very healthy. But the testimony of Herodotus is clear and pointed on this subject. He says, that "after "the Africans, there is no people in health and constitu"tion to be compared with the Egyptians. To this ad(6 vantage, the climate, which here is subject to no varia"tion, may effectually contribute." While the Egyptians were governed by their native princes, and while they continued to be industrious, Egypt was a healthy country. But after those people had been reduced to a foreign yoke, the spirit of enterprise forsook the land; their canals were neglected, the waters stagnated on the surface, and pestilential diseases were promoted. We have no correct information when it was that the disease, emphatically called the plague, first appeared in the world. It seems to have originated long before the small pox, but the native place of neither can be traced. The Carthaginians were afflicted by the plague at least two thousand three hundred years ago. Thucydides speaks of a plague that wasted Athens, about 2280 years ago. Procopius speaks of a plague that appeared about the 540th year of the Christian era, which threatened the very existence of the human race. It did not come, as he says, upon one part of the world alone, nor in one season of the year. It afflicted the whole world, and all conditions of men, sparing none. Some took it in summer, and some in winter. It spared neither island, cave, nor mountain,