CAUSES.-RACE. three thousand five hundred and seventy-six. In Ecija, an interior town of Seville, some eighty miles from the sea, the male mortality was one thousand three hundred and eighty, and the female two thousand four hundred and twenty-two. The aggregate mortality in Charleston, S. C., during ten years, between 1817 and 1839, was as follows: Males, nine hundred and seventy-six: females, one hundred and seventy-eight. SEC. VI.-Race. The African race is less liable to yellow fever than the Caucasian. The comparative exemption of negroes from the disease has long been noticed. During the Philadelphia epidemic of 1793, Dr. Rush published in one of the daily newspapers the following extract from Dr. Lining's History of the Yellow Fever, as it had four times appeared in Charleston, South Carolina: "There is something very singular in the constitution of the negroes, which renders them not liable to this fever; for though many of them were as much exposed as the nurses to the infection, yet I never knew of one instance of this fever amongst them, though they are equally subject with the white people to the bilious fever." In consequence of this publication, the African Society voluntarily "It was not offered to furnish nurses and attendants for the sick. long," continues Dr. Rush, "after these worthy Africans undertook the execution of their humane offer of services to the sick, before I was convinced I had been mistaken. They took the disease in common with the white people, and many of them died with it. A large number of them were my patients. The disease was lighter in them than in white people. I met with no case of hemorrhage in a black patient." Dr. Lewis, in his account of the Mobile epidemic of 1843, says: "Negroes were frequent subjects of fever; these cases were similar to the mild grade of the yellow fever of the season, yet never, as far as my observation extended, arriving at the stage of black vomit; nor did a single case prove fatal in my practice amongst this class of persons. Some four or five mulattoes died of black vomit, during the season. Many cases terminated in the characteristic hemorrhages, and others again passed through all the stages of grave yellow fever, requiring the same active stimulation to sustain them in the collapse stage that were used under similar circumstances with the whites. These cases were confined to the mulattoes. Notwithstanding the great Reports, etc., by Sir J. Fellowes, p. 478. 2 Rush's Med. Inq., vol. iii. p. 80. fatality that attended this class in 1813, we are bound to conclude that, as a general rule, they are exempt from the noxious influence of the poison of yellow fever. They constitute, especially in autumn, a large portion of our population; many of them recently from Virginia, and the Carolinas, coming strictly under the head of unacclimated persons. Those unacclimated suffer more than those long resident amongst us; still, they have black vomit so seldom as scarcely to constitute an exception to the general rule." In 1820, says Dr. Daniell, near three hundred native Africans, recently captured on the coast, by government vessels, were brought into Savannah. They remained there during an epidemic yellow fever, but not one suffered from the disease. Dr. Dickson says he has never known an African negro to be attacked by yellow fever.3 SEC. VII.-Constitution. It would seem that yellow fever is more likely to attack the stout and plethoric than the more feeble and delicate. Mosely says the disease is incidental only to the gross, inflammatory, and plethoric; and again: "Subjects most likely to be attacked by the Endemial Causus, are the florid, the gross, the plethoric-that sort of strong, full, youthful people, with tense fibres, who in England are said to resemble the picture of health." Sir Gilbert Blane says: "Those who are young, fat, and plethoric, are most apt to be attacked; and more of our officers in proportion were seized with it than the common men." It should be remembered that a pretty large proportion of the unacclimated are likely to consist of this class of persons-the young, active, and robust, coming from cooler climates. SEC. VIII.-Occupation. The largest number of persons destroyed by yellow fever are soldiers and sailors, the reasons for which are sufficiently obvious. It is alleged, by many writers, that there are certain occupations which render persons engaged in them to a great extent exempt from the disease. This has been said to be the case with butchers, and workers in leather, soap, and tallow. I do not think there is any good reason for this opinionthe evidence upon which it is founded, so far as I can judge, being altogether inadequate. Dr. Gillkrest says: "Circumstances connected with localities being equal, the upper classes of society seem, on all occasions, to suffer from attacks in a full proportion." N. O. Med. Journ., vol. i. p. 416. 3 Dickson's Essays, &c., vol. i. p. 345. 2 Fevers of Savannah, p. 64. Obs. Dis. Seamen, p. 398. CAUSES.-ACCLIMATION. Matthew Carey, in his account of the Philadelphia epidemic of 1793, says: "To the filles de joie, it has been very fatal. The wretched debilitated state of their constitutions rendered them an easy prey to this dreadful disorder, which very soon terminated their miserable career. To hired servant-maids it has been very destructive. Numbers of them fled away; of those who remained, very many fell, who had behaved with an extraordinary degree of fidelity." In this connection it may be added, that all the attendants upon the General Hospital of Barcelona, during the epidemic of 1821, who died with yellow fever, are said to have been suffering at the time under chronic diseases. Dr. O'Halloran says the physicians of Barcelona generally remark that scarcely an individual escapes an attack of yellow fever who labors under venereal or chronic disease. 2 SEC. IX.-Acclimation. In this chapter, more appropriately than anywhere else, may be placed a few remarks upon the influence of a prolonged residence in yellow-fever localities, in rendering the system unsusceptible to the poison of the disease. This change in the system is called acclimation. It is most speedily and effectually wrought by the occurrence of the disease itself; but it is quite evident that it may be more slowly and gradually effected by a continued residence in yellow-fever regions. The precise conditions and causes of this exemption have not been very positively ascer-. tained, and it is probable that they vary somewhat in different cases. There is a great difference, in different seasons and places, in the degree of protection afforded by this modification of the system. During mild epidemics, the protection is quite perfect; but when the character of the disease is highly malignant, the protection in many instances wholly fails. Some observations relating to this subject, by Dr. Lewis, will be found in the chapter on bibliography. He says, further, that "Of one hundred and twenty cases that terminated fatally at Mobile, in 1843, seven were natives, three were from Charleston, five from New Orleans; twenty had resided in Mobile from five to ten years, annually avoiding the sickly months; fifteen had been constantly in the city from four to seven years-amongst whom were four who had the fever in 1839. Sixty were strangers, never having passed a summer in a yellow-fever locality. These facts tend to the following conclusions: 1 Carey's Short Account, etc., p. 61. 2 O'Halloran on Yellow Fever, p. 98. In healthy years what is called sporadic yellow fever is confined to strangers. In years when the disease does not prevail so generally as to amount to an epidemic, the grave cases are confined to the unacclimated. In epidemics, the natives, old residents, and even those who have had the disease in previous years, are frequently mildly attacked; but the strangers are very generally seized, and have, in fact, to bear the violence and malignity which belong to the fever." It would seem that this protective power of acclimation does not extend to localities which are usually exempt from the disease. A very remarkable circumstance in support of this remark occurred at Woodville, in Mississippi, in 1844. This inland town then contained about eight hundred inhabitants, mostly natives, or old and permanent residents. At least, it is stated that the town had been of gradual growth for forty years, and that there had been no sudden emigration. After the appearance of yellow fever in the town, nearly two hundred persons fled to the surrounding country; but nearly all who remained were attacked by the disease. Dr. Stone, in his report, says: "Few persons escaped; I know of not more. than five adults, and no children, except those persons, about twenty in number, who had yellow fever formerly. Of these, one had it in Charleston, forty years ago, others in New Orleans, Bayou Sara, Natchez, the West Indies, and elsewhere; and all escaped, with perhaps one exception, a mild case." The great endemic of the western coast of Africa is periodical fever, but yellow fever has occasionally appeared at some of the settlements. It prevailed at Sierra Leone in 1823 and in 1829, and was as fatal amongst the old residents as the new-comers.3 It would seem that at certain times, and in certain localities, the poison of yellow fever acquires such an intensity as to overbear all the influences which ordinarily resist it. Everything gives way before it; neither age, sex, nor race is spared, and not even the most thorough acclimation, nor the previous occurrence of the disease, is sufficient to ward off its assaults. This preservative influence of acclimation seems to be pretty readily lost or destroyed, or at least greatly diminished, by a removal from yellow-fever regions to cooler latitudes. Bally reports the case of a lady who, born in Canada, had resided for N. O. Med. Journ., vol. i. p. 418. Ibid., p. 532. thirty years in one of the Antilles. After an absence of two years, passed in the North, she returned, and soon after died with yellow fever at the age of fifty-four years.' SEC. X.-Exemption from Subsequent Attacks. Yellow fever very rarely occurs a second time in the same individual. This exemption from a second attack of the disease was noticed during the last century; and it has been since corroborated by the observations of many French, English, Spanish, and American physicians, amongst the earliest and most distinguished of whom were Professor Arejula and Sir William Pym. This point in the natural history of yellow fever was made the subject of a special and formal investigation after the cessation of the epidemic at Gibraltar in 1828. At the instance of Sir William Pym, a commission was appointed for the express purpose of collecting such facts as might settle the question. The commission consisted of thirteen physicians, French, English, and Spanish. Louis was appointed President, Dr. Barry Vice-President, and Trousseau Secretary. The distinguished Chervin was also a member of the commission. The medical men of Gibraltar, civil and military, thirty-three in number, all of whom had been familiar with the disease, appeared before the commission, and stated the results of their experience. The aggregate number of patients with the disease, seen or treated by them all, amounted to about twenty-seven thousand. These physicians were invited to state the number of cases in which they had known the disease to occur a second time; and as simple assertions were inadmissible, the commission decided that they would receive those cases only in which the symptoms of the first and second attacks could be given, whether these symptoms had been noted by the physicians who communicated them, or whether they came through the patient himself, but were unequivocal. The whole number of cases of presumed double attack thus communicated to the commission was only thirteen! Upon these thirteen cases, each member of the commission expressed his opinion by a vote, writing upon a piece of paper the word evident, probable, doubtful, or inad missible for each case. A majority of the commission declared, in this manner, one of the cases evident, three of them probable, and the remainder doubtful or inadmissible. The following fact, on a much smaller scale, but hardly less conclusive, was communicated Devèze, p. 107. |