malignant or congestive character, like Asiatic cholera, scarlatina, typhus fever, and so on, are all in favor of this interpretation. [For the discovery of one of these immediate or remote effects, it now seems that the profession is indebted to Dr. Collings; and in confirmation of the opinions expressed in this section, it will be interesting to read the following extracts from Dr. Blair's Report. "The mode of death in uncomplicated yellow fever has four varieties, and these are sometimes blended, viz., Syncope, uræmia, apoplexy, and asphyxia. When the black vomit is plentiful, or the urine. free, the intellect remains clear and unclouded; but the skin becomes cold and damp, the pulse small, and finally extinct at the wrist, and the patient dies of gradual exhaustion and syncope" (often called collapse). Death by syncope is often the result of hemorrhage, or of hemorrhage and black vomit combined, and in some instances probably of black vomit retained. Again, "if before death the urine be suppressed, and the black vomit be not copious or has ceased, the circulation becomes contaminated (uræmic); and when this condition operates on the brain in its mildest form, the effect is not unlike alcoholic inebriation; as in the case of the master of the Hindu, who on the night of his death, sat up in bed, drank beverages, and joked with the shipmasters around him; and the carpenter of the Eleanor, whom within a few hours of his death, and while pulseless, I found sitting up in his chair and regaling himself with his tobacco pipe. If all the secretions be locked up, the symptoms of uræmic poison become violent, the sensorium painfully affected; irritability of temper, screams and wild ravings, coma and convulsions ensue." "The mode of death by apoplexy, caused by congestion, effusion and extravasation of the blood in the brain," is illustrated by reference to certain cases. And finally "instances of death by asphyxia" are named, one by "laryngeal suffocation," and two by "pulmonary apoplexia." But all the deaths do not occur in these ways, and "the causes that disturb the current course of the morbid phenomena, have not yet been satisfactorily investigated." "The essential modes of death," he adds, "are (also) modified by those inflammatory complications to which yellow fever is so liable in its course." Among them, he names pericarditis, inflammation of the lymphatics, and pneumonia, &c.] CHAPTER IV. CAUSES. IN the multitudinous records of the history and literature of yellow fever, there is no portion so involved in interminable confusion and embroilment as that which relates to its causes. After as thorough and careful an examination as time and opportunity have enabled me to make, I shall now do what I can in endeavoring to render this subject as intelligible as its nature and present condition will admit, following the same general plan by which I have been guided in the preceding portions of my book. SEC. I.-Locality. Amongst the most striking circumstances in connection with the etiology of yellow fever are those of the geographical boundaries within which it is confined, and the more circumscribed localities in which it prevails. In the first place, the disease is very rarely met with south of the twentieth degree of south, or north of the fortieth degree of north latitude. The range of latitude in which it prevails most extensively lies between thirtysix or thirty-seven, and forty-one or forty-two degrees north, in Europe; and between ten and thirty-five degrees north, in America. In the second place, even within these limits, yellow fever is much more frequent in the Western than it is in the Eastern hemisphere; and still further, it is much more common in certain portions of Europe and America than it is in Africa. In the third place, yellow fever is almost always confined to commercial seaports, although it is occasionally met with in the towns and cities in the neighborhood of the latter, situated in the interior of the country, or on the banks of navigable rivers. In the fourth place, yellow fever is very frequently strictly circumscribed within certain limited and well-defined portions of the locality, or in the city in which it prevails. These four facts, in connection with this element of the etiology of the disease, are well ascertained; there is no doubt, that I am aware of, or difference of opinion in regard to them. . The places in Europe which have been most frequently and most extensively visited by this disease, are the seaports of the north coast of the Mediterranean, especially those of Spain. Dr. Gillkrest enumerates eighty-five towns or cities in the maritime provinces of Andalusia, Murcia, Valencia, and Catalonia, where yellow fever has been known to prevail. The most important of these are Cadiz, Gibraltar, Malaga, Carthagena, Alicante, and Barcelona, all situated on the sea-coast. Dr. Gillkrest says, further, that the disease is occasionally met with, to a limited extent, in some of the towns and cities at a considerable distance from the sea; amongst these, he mentions Cordova, situated on the Guadalquivir, seventy miles in a direct line from the coast, and Ronda, sixty miles north of Gibraltar. Similar facts are of frequent occurrence in the United States. The interior towns, which are oftenest visited by yellow fever, are those situated above New Orleans, on the Mississippi River, especially Natchez and Vicksburg. In 1844, Woodville, a small inland town of Mississippi, fifteen miles in a direct line from the river, suffered severely from the disease, as did also many isolated plantations in the surrounding country.1 The principal seats of the disease, in America, are the towns and cities lying along the shores of the Atlantic Ocean, from Charleston south; along those of the entire Gulf of Mexico, and of most of the West India Islands. The shores of this western Archipelago and Gulf constitute the great and prolific hot-bed, in which is constantly generated the unknown poison of the disease; they have been the crowded Necropolis of the successive swarms of adventurers and invaders, who have annually flocked thither from Europe and America, ever since their discovery. Chisholm says, in his dedication, that more than twelve thousand of his countrymen have perished within these islands in the short space of two years! In connection with the localities, or the habitat, of yellow fever, it is important to notice that it frequently occurs and prevails extensively on shipboard. This has been so often witnessed as to render it quite certain that, in yellow fever seasons, and places, the hold of a ship often constitutes a very prolific nidus for the generation of the poison of the disease. Dr. Gillkrest enumerates nearly forty vessels or squadrons, in which, at different periods, the disease has appeared. The first appearance of yellow fever on shipboard usually takes place while vessels are in port, or very soon after 1 N. O. Med. Journ., vol. i. p. 530. 2 Cyc. Prac. Med., vol. ii. p. 270. they have left port. Dr. Burnett, who saw a great deal of the disease in the ships of the British fleet on the Mediterranean station, says that, with one exception, he never knew an instance where the crew of a vessel were attacked after being some time at sea.' Dr. Currie, of Philadelphia, supposed that crowded transports, or ships of war, generally, if not always, constituted the original and proper sources of the matter of contagion, or the poison of the disease. Dr. Barrington says that the disease made its appearance on board the United States ship Hornet in 1828, while lying at Sacrificios, a small island about three miles from Vera Cruz. The ship had been lying there at anchor twenty-six days when the first decided case occurred; there was no epidemic in the city of Vera Cruz, excepting the dengue; nor was the fever prevalent at any place where the vessel had touched during her cruise. There can hardly be a doubt as to the origin of the disease, here, in the ship. Other cases of a like character are on record. In 1799, the frigate General Green sailed from Newport, Rhode Island, for Havana. She had tempestuous weather, leaked badly, and became very foul, the weather being excessively hot. Yellow fever appeared amongst her crew before she arrived in port, which was at the time free from the disease.3 M. Chervin has collected a considerable number of similar instances, which seem to be well authenticated, and which, so far as I know, are uncontradicted. [The proofs of the origin of yellow fever on shipboard, without "the operation of external agencies, or the introduction of contagious germs," have been lately collected by Dr. La Roche. His argument is cumulative, and apparently conclusive.] There is another circumstance, in connection with the prevalence of yellow fever on shipboard, which ought to be stated. The disease is said in many instances to be confined to certain portions of the ship; or at least to prevail more extensively in certain portions than in others. Dr. Wilson says: "It is always at the beginning confined to a small space. It often continues for a while in one berth, whence it sometimes crosses to the opposite berth; sometimes it travels along one side, returning pretty regularly by the 1 Burnett on the Med. Fever, p. 3. * Devèze, p. 158. Rapport de l'Acad. Roy. de Méd., 1827, p. 9. 2 Currie's Dis. of Am., p. 60. 6 [Facts and Observations on the Origin of Yellow Fever from Local Sources of Infection, &c. Am. Journ. of Med. Science, April, 1853. Also, "Yellow Fever," by R. La Roche, M. D., &c., vol. ii. pp. 421-456.] other; and sometimes it traverses the ship from the rear to the forepart, or in a contrary direction. But in a majority of instances, it begins in the vicinity of the pumps and main hatchway, where the shell of the ship is most dependent, where water draining from other parts collects, and where heat is most intense."" The fact of the limitation of yellow fever to certain well-defined quarters, or neighborhoods, of the cities in which it is epidemic, has been so generally observed, that it is hardly necessary to multiply examples of this limitation. The extension of the boundaries of this infected district, as it is called, almost always takes place gradually. Dr. Nott, of Mobile, in a private letter to me, says: "I have, on two occasions, seen yellow fever commence in a point in the town, and eat through it, square by square, like worms in a cotton field-taking each time nearly a month for this process." Arejula, in his account of the epidemic of Cadiz, in 1800, says: "We also ascertained that the disorder not only spread from one individual to another, but that it passed from one house to the next adjoining, and so on along the street, ultimately affecting the whole district."* Arejula also gives an account of the origin and spreading of the disease at Malaga, in 1803. He traced it regularly and gradually from its focus, first to one house, then to another adjoining, and so on through a whole street or district. M. Berthe, who was one of the French commission to investigate the epidemic of Andalusia, in 1800, says: "It was distinctly observed that the malady affected to seize, with scarcely any interruption, all the houses which were situated on the same side of a street, and that it rarely passed over to the other side, where the streets were wide and well aired. In some parts of the town, the distemper had been seen to stop, as it were, for a time, as soon as it had reached to houses standing in a public square, and even to retrograde with respect to the direction in which it had previously advanced, by appearing in the adjoining houses, rather than in those which were separated by the breadth of the square." The Cadiz epidemic of 1800 commenced in a quarter of the city called the Barrio de Santa Maria, to which quarter it was at first confined; it gradually spread to other portions of the city. The same thing is true of other epidemics. Dr. Hosack says: "Whenever the yellow fever has been introduced into the cities of the United States, its first extension has always 1 Memoirs of West Indian Fever, p. 157. 2 Reports, etc., by Sir J. Fellowes, p. 36. 4 Bancroft's Essay, p. 459. |