Yellow Fever
an infectious continued fever, us ushered in with languor, chilliness, and and more or less severe lumbar pains and frontal headache, headache, countenance flushed, eyes at first humid, then suffused, and ultimately ferretty, skin imparting a tingling heat to the touch, and, as the second stage advances, gradually acquiring a lemon or greenishyellow tinge, mind usually disturbed with hallucinations, or more or less violent delirium, restless watchfulness, or, possibly, drowsiness even to extreme coma, epigastric uneasiness, spontaneous vomiting without effort, first of a clear glairy fluid, but subsequently with coffee-ground flocculi, or blood itself, often, toward the close, with irrepressible hiccough, and wild shrieking or melancholy wailing, tendency fatal, but the disease generally confers an immunity from subsequent attacks. The first recorded outbreak of yellow fever occurred in the West Indies in 1647, and since that time it has been recurring at regular intervals in an epidemic form, and gradually extending its range; but it is endemic in certain lo- YELLOW FEVER calities, and notably so in the islands of St. Thomas and Santo Domingo. Regarding its altitudinal and horizontal ranges Dr. Macdonald says: "It may be very well to assign an altitudinal limit of the spread of yellow fever, and, roughly speaking, this may be estimated at between 2,000 and 3,000 feet above the level of the sea, but the local conditions of every country seem to determine a range peculiar to itself. Thus the disease has been known at Newcastle, Jamaica, at an elevation of 4,000 feet, while in the valley of the Mississippi its highest recorded range is about 600 feet (admitting the fever of Gallipolis to be of the genuine type). Humboldt alludes to the farm of Encero, in Mexico, at an elevation of 3,243 feet, as the altitudinal limit of the black vomit. At Santo Domingo the encampments of the French in 1792 and of the English in 1796 enjoyed an immunity ity from the disease, while it was spread far and wide among the troops in the low country. Though the West Indian Islands, and the neighboring coasts of North and South America, may be looked on as the focal area of yellow fever, yet, taking the outlying points at which its occurrence in the epidemic form has been recorded, its geographical range must be regarded as very considerable indeed, i. e., between lon. 97° W. and 2° E., and between lat. 48° N. and 35° S. At least for the space of a century and a half, up to the year 1850, the Amazon river, dividing the Brazils from Guiana, limited the extension of yellow fever S. of the line; and while the disease was raging at Rio and Bahia, at the close of that epoch, the Montevideans flattered themselves that they were without the geographical limits of the pestilence, till it fell to their turn to sustain its visitation several years later, when the illusion was dispelled.
Similar facts may be adduced regarding the extension of the disease along the shores of the Pacific; so that, however well we may be acquainted with its present range, making all due allowance for temperature, we cannot tell what the future may bring forth. In this connection it may be mentioned that a temperature of at least 72° is assumed to be essential to the development of yellow fever, though cases exceptional to this rule may now and then happen. Yellow fever is communicated from one person to another only by a species of house mosquito (Stegomyia fasciata). As a result of this knowledge it was entirely eliminated from the Panama Canal zone, and from other tropical areas, including Havana.
In December, 1878, a board of experts, YELLOW SEA consisting of twelve medical men and a sanitary engineer, with Surgeon-General Woodworth as president, was appointed by the Health Committees of the Senate and House of Representatives of the Congress of the United States to investigate the yellow fever epidemic, and they came to the following conclusions : (1) Yellow fever is a specific disease, due to a specific poison which has not been chemically or microscopically demonstrated, nor in any way made evident to the human senses; it is material and particulate, and endowed with the vital properties of growth and reproduction; disease is malarial, influences do not contribute toward its dissemination or mortality to any greater extent than to other epidemic diseases; a concurrence of local conditions seems to be necessary to the evolution of the disease, but what these are we have no positive knowledge. (2) Yellow fever is a disease of singular local attachments, often prevailing in a very small section of a city, with remarkable indifference to topographical and social surroundings; while atmospheric air is the usual medium by which it is conveyed, it has been in no instance established that the disease has been carried to any considerable distance by atmospheric currents, or by any modes or vehicles of conveyance other than those connected with human traffic and travel; the period of incubation varies from two to five days; the fever is unknown in Asia; the white race is most susceptible to its influence, and furnishes the highest ratio of deaths.
YELLOW SEA (Chinese, Whang Hai), an arm of the Pacific Ocean; on the N. E. coast of China; length about 620 miles; greatest breadth, about 400 miles. It is very shallow, and obtains its name from the lemonyellow color of its water near the land, caused by mud suspended in the water from the inflow of the Hoang-ho and Yangtse -kiang rivers.