The climate of the southern part of China, according to the same author, is excessively hot during the summer months. Even in September and October, when the nights are cold, the days continue to be sultry. The cold months are, December, January and February; “and during this time the vicissitudes of the weather are more quick than in any other part of the world. When the wind is northerly, and the thermometer at 46, upon a change of the wind to the south, it is next day up to 60 or 70. People who reside here are always at a loss with regard to their clothing; one day finding a silk coat sufficient; and the next, upon a sudden change of wind, finding it necessary to wear a flannel waistcoat.”
On the subject of climate, therefore, I must conclude with the following observations:—First: That, as the diseases above mentioned are produced both in moist and dry countries, in those in the torrid and those in the temperate zone, they can neither be the offspring of moisture or drought, of heat or cold, of septics or antiseptics, but of something not yet discovered. Second: That, upon fair investigation, it does not appear, that ancient historians have been able to ascertain the origin of any plague whatever: they have universally ascribed it to the anger of the Deity, while their own pride would never allow it to have originated in any country with which they were connected. Third: It doth not by any means appear, that the climates of those countries, where the plague is known to be most common, are at all inferior to those already described, excepting the very circumstance of having the plague frequently in them: nay, indeed, that they are equally bad. Nobody will pretend to argue, that the climate of Asia Minor, of Greece, of the Morea, or of any of the countries most infected with the plague, was, or is, worse than that of Catchou in Africa, already described; yet it is certain, that we have a number of testimonies that the plague has ravaged Asia Minor, while we have not one of its visiting Catchou. Ancient Greece, the Peloponnesus (Morea) and Asia Minor, were accounted healthy and fine countries; and modern travellers assure us, that they have not degenerated in this respect; yet these countries are desolated by the plague, while the unwholesome regions above described are entirely free from it, unless imported from some other quarter. To give this matter, however, as fair a discussion as possible, I shall here consider the account we have of the climate of Bassorah, given by the gentleman residing there in 1780; whose case, in the remitting fever, is given, Appendix, No. VI. “The overflowing of the Euphrates, and its waters stagnating in the desert, have always been accounted primary causes of epidemical diseases at Bassorah. The great floods from the melting of the snow on the mountains of Diarbekir, the ancient Assyria, happened in the year 1780, early in the month of May, when the heats in Persia and Arabia begin to be excessive. The desert, which reaches to the gates of Bassorah, is, for many miles, incrusted with a surface of salt; which, when mixed with the stagnated waters, and exposed to the sun, produces the most noxious effluvia. As early as the 25th of May, the town was surrounded by a salt marsh, the heated steam arising from which was, at times, almost intolerable; but the canal that runs through a great part of the city being filled with the bodies of animals, and all kinds of putrid matter; and, at low tides, all these substances exposed to the sun, made the air in the town scarce supportable; and, being totally destitute of police, the streets were in many places covered with human ordure, the bodies of dead dogs and cats, &c. which emitted a stench more disagreeable and putrid than any thing I ever experienced in my life. As to the degree of solar heat, it far exceeded what I conceived the human frame to be capable of bearing. The sensation under this heat was totally different from what I had ever experienced; it resembled the approach of an heated substance to the body. The quicksilver, in Fahrenheit’s thermometer, rose to between 156 and 162 degrees.[28] From the 30th of May I never saw it so low as 156, but generally between 158 and 160. After I left Bassorah I was told that it rose still higher. In the coolest part of the house, with the aid of every invention to decrease the heat, the quicksilver rose to 115; but after I came away, I was informed that it rose still higher, even at seven in the morning, the hour which we accounted the coolest in the day. Once the heat was said to be so intolerable, that no one could expose himself to it long enough to observe the thermometer in the sun. Some of the oldest inhabitants of Bassorah said that they never remembered to have heard of such a heat in any part of Persia or Arabia. The natives of the country appeared more alarmed at the heat than the Europeans: nothing could induce them to expose themselves to the sun after ten o’clock. I left Bassorah for Aleppo on the 30th of May. On our arrival at Zabira, the heat was so intense, that even the Arabs sunk under it.”
From this account it was natural to expect that violent sickness would ensue. This was the opinion of the inhabitants, and they were not deceived. The sickness, however, was not the true plague, but a violent remitting fever; and even this did not originate in the city itself, but was observed to approach from Asia Minor, ravaging Diarbekir, and keeping the course of the Tigris, to Bagdad, where many died. From thence it followed the course of the Euphrates to Bassorah, and for about twenty miles lower. The opposite, or Persian shore, though within a few miles, was exempted, and it did not spread more than twenty miles into the desert.[29]
I might now proceed to give an abstract of what has been said of the power of climate in producing diseases on the Western Continent, and West India islands; but as this belongs more especially to the second part of this Treatise, I shall here pass it over, as well as what Dr. Smith has said of the climate of Greece, in the Medical Repository, and which he endeavours to prove to be similar to the climate of North America. But, before we proceed to consider what diseases may be produced by climate alone, it is proper to discuss the question, how far man is naturally subject to diseases of any kind? Many, no doubt, will be apt to suppose this a very absurd question; for as man is now, by nature, subject to death, it seems to follow, that he is also naturally subject to disease, as the means of bringing on death. But, however plausible this may appear, experience shows, that disease and death are not always connected. Many people die of mere old age; the powers of life being exhausted, and the system so far decayed, that the various parts of it can no longer perform their offices. On the other hand, a disease destroys by attacking some particular organ, and either totally consuming or altering it in such a manner, that it disturbs the vital operations, while yet strong and vigorous. We may therefore compare the death of a person from mere old age to the natural extinction of a candle when the tallow is totally consumed; and death from disease, to the blowing out of a candle while a part of it remains, and might have burned for a considerably longer time. Thus I am inclined to consider all diseases as merely accidental; and this with the greater certainty, because, though, in common with other believers in revealed religion, I think that death is the consequence of Adam’s transgression, yet I do not find that disease of any kind was threatened except in cases of positive transgression, long after the days of Adam.
Every one allows, that, though some diseases are natural, some are likewise artificial; but nobody hath attempted to draw the line of demarcation between them. Every thing is charged upon climate, heat, moisture, drought, vapour, &c. and yet, upon examination, we shall find the utmost difficulty in deriving a single disease from the causes we assign. No person in his senses will say that Adam, in consequence of eating the forbidden fruit, became liable to the venereal disease. As little can we say for the gout, the stone, or the dropsy; and if we cannot particularize the diseases to which he became naturally liable, we have no right to say that any kind of disease became natural to him in consequence of his transgression. If, therefore, death itself, originally not natural to man, did yet take place in consequence of his moral conduct; and if diseases, without number, have arisen among his posterity, though not natural to him in consequence of his first transgression, we have equal reason to believe that these diseases have taken place among them in consequence of their moral or rather immoral conduct, in totally deviating from the line prescribed them by their Maker, and following others of their own invention; and this will appear the more probable, when we consider, that, long after mankind became subject to death, we find diseases, particularly the pestilence, threatened as the consequence of subsequent transgressions.
If, without taking scripture into consideration, we attend only to what may be gathered from profane history, we find the testimony of all the ancients concurring in one general point, viz. that in times of great antiquity men were more healthy, and even stronger, than in the times when those authors lived. This is taken notice of by Homer, when comparing the strength of men in the time of the Trojan war with those in his days, about two centuries later.[30] Virgil, who lived in much more modern times than Homer, carries his ideas of the degeneracy of man much farther; and informs us, that Turnus, when fighting with Æneas, took up and threw a stone which twelve men of that time could not have lifted. Now, though we know that both these accounts are fabulous, yet they perfectly coincide with the voice of historians of all nations; for we are universally told, that the first inhabitants of countries were a brave, hardy people, living according to the simplicity of nature, free from diseases, and attaining to a good old age.
This is so conformable to what is generally said at present, probably very often by rote, without regard to rational evidence, that, were we so inclined, ample room might be found for declamation against modern luxuries, particularly the practice of drinking ardent spirits, as pernicious to health, and destructive to the human body. On this subject, however, we may once for all observe, that, although we find ample evidence of the baleful influence of these liquors in producing other diseases, yet we find none of their ever having had any share in the production of an epidemic or general disease among mankind. In ancient times the art of distillation seems to have been unknown; so that whatever mischief was done in those days must have been done by wine, or other fermented liquors. In modern times, though the use both of fermented liquors and ardent spirits is undoubtedly carried to excess, yet there is no evidence of their producing an epidemic, or even making it more violent or general than it would otherwise have been. Dr. Cleghorn, having spoken largely of the manner of living of the natives in Minorca, proceeds thus: “I should next give a circumstantial account of the diet and way of life of the British soldiers in this island; but as this would be a disagreeable task, I shall only observe, that the excess of drinking is among them an universal vice, confirmed into habit. But, however different the Spaniards be from the English, in their meat, drink, exercise, affections of the mind, and habit of body; yet the health of both nations is equally influenced by the seasons. An epidemical distemper seldom or never attacks the one class of inhabitants without attacking the other also; and, surprising as it may appear, it is nevertheless true, that the peasants, remarkable for temperance and regularity, and the soldiers, who, without meat and clothes, frequently lie abroad drunk, exposed to all weathers, have diseases almost similar, both as to their violence and duration.”
There can be no doubt that excess in drinking hath put an end to the lives of many individuals; and it hath been observed, that such as attempt to preserve themselves from the plague by the use of strong liquors, have generally fallen sacrifices to it;[31] but this cannot prove that such excess would have brought on the distemper without some other cause. It hath been certainly found, that excess in drinking or eating, excess in venery, excessive fatigue by labour, watching, study, &c. will all make an epidemic disease more violent when it attacks a particular person; but no experience hath yet shown that the first person seized with an epidemic always fell under this description. All that can be said on the subject is, that, by such excesses as have already been described, the body is prepared for receiving the disease, by an exhaustion, or evaporation (if we please to call it so) of the vital principle; as wood is prepared for burning by the evaporation of its moisture; but as wood, however dry, will not burn without the contact or application of fire, so neither will the body, though ever so well prepared, be attacked by any epidemic, unless the true cause of that epidemic be also applied.
Thus we are still disappointed in our attempts to discover the origin of the plague. We have seen that the most unhealthy climates in the world do not produce it of themselves; neither can the conduct of any individual bring it upon himself, without an unknown something, which nobody has yet found out. It was this difficulty of finding out the natural cause, which certainly induced by far the greatest number of writers on the subject to ascribe it to Divine Power; and even as late a writer as Dr. Hodges tells us, that he believes in the to Theion, the “finger of God,” in the plague, as much as any body. As for those who have endeavoured to account for the origin of this distemper from an inquiry into natural causes, and conclusions drawn from the late experiments on air, they have totally failed; as will be fully elucidated in the following section.
If then we are to believe that diseases, especially those called epidemics, among which the plague holds the first place, have arisen in consequence of a certain line of conduct adopted by the human race, or have been inflicted by the Deity as punishments on that account, we are to look for their origin among those to whom the Deity principally manifested himself; that is, the Jews, and nations who interfered with them. Among the Jews we hear of the first general plague distinctly mentioned; viz. the three days pestilence of David, and to which it is possible that Homer alludes in his Iliad. Next to this is the great plague of 767 B. C. said to have spread all over the world. This coincides with the time of Pul, king of Assyria; who, having overthrown the ancient kingdom of Syria, turned his arms against that of Israel, and no doubt extended his conquests among the eastern nations, as we know very well the Assyrian monarchs did. As the ten tribes, ever after their separation from the house of David, had in a manner totally given themselves up to idolatry, we are not to wonder if the pestilence, so frequently threatened by Moses, was very common, or, as physicians term it, endemic, among them. Thus, whatever enemy invaded the country, would almost certainly carry the disease along with them, and spread it among the other nations with whom they afterwards had any connexion. At this time, or even before this, during the wars of Syria with Israel and Judah, this dreadful pestilence might begin; but, as to its being all over the world in any particular year, I do not see how it can be ascertained; because there are no general histories of the world in those early times. It appears more probable that this general pestilence took place at the time that Sennacherib’s army was destroyed. I have no doubt, indeed, for the reasons already given, that the plague had infected Sennacherib’s army before he went into Ethiopia. In that country, in all probability, he would leave it; and, after his return to Judea, when the dreadful catastrophe befel him of an hundred and eighty-five thousand of his men being destroyed in one night, there can be no doubt that the remains of his army would carry with them the seeds of a most malignant pestilence, capable of spreading destruction far and wide. It is true, we are not directly told, in Scripture, that the Assyrian army was destroyed by a plague, but that the angel of the Lord destroyed them; but, as this expression is quite similar to what we read of the pestilence in David’s time, there can be but little doubt that the means of destruction made use of in both cases were the same. Josephus expressly says, that Sennacherib’s army was destroyed by a pestilence. Neither are we to conclude, because this pestilence was miraculous, that it therefore certainly killed every one on whom it fell; or that it would not infect those who came near the sick, as any other disease of the kind would do.