YELLOW FEVER.—An acute, infectious disease, which runs a rapid course, and which is restricted principally to the warm countries of the Western Hemisphere, occurring mainly in populous cities with maritime traffic. In Europe, only the south-western countries, especially. Spain and Portugal, have been visited by severe epidemics. It has been observed that epidemics have frequently occurred on ships sailing from infected ports.
The disease is caused by a certain poison, the nature of which is not known as yet. It appears, according to the most recent investigations, that mosquitoes play a part in the transmission of the disease, as is the case with malaria. It is certain that the poison, in order to develop, requires warmth and humidity. It is not believed that the affection can be transmitted by human beings, or by maritime traffic, without the agency of mosquitoes. The interval between infection and the outbreak of the disease is usually two or three days, seldom more than five.
The onset of yellow fever is usually marked by a sudden chill, followed by fever. The patient at once feels seriously ill. The face becomes markedly red and swollen, and also the conjunctiwe of the eves becomes red. Great thirst prevails, with pressure and marked tenderness in the region of the stomach, sometimes accompanied with vomiting, often with consti pation. Jaundice sets in, generally toward the end of the first stage of the disease (which lasts several days to a week), sometimes later. The fourth day usually witnesses a considerable abatement of almost all the symptoms of the disease. In severe cases this apparent improvement is followed by an aggravation of the condition, in which vomiting is one of the principal symptoms. Small quantities of blood are mixed with the vomitus, and, later, it may happen that black masses. resembling coffee-grounds, are thrown up. These masses consist of blood, which is changed by the acids of the stomach. This so-called " black vomit " is dreaded as a very grave symptom. In fatal cases, similar masses are discharged with the stools. 1-emorrhages frequently occur also in other organs: from the nose, from the mouth, into the skin, etc. The secretion of urine may be entirely suppressed ; and this is always a fatal sign. Death usually takes place between the fourth and tenth days of the disease. The mortality in the different epidemics fluctuates between 15 and 75 per cent.
The disease requires the immediate attention of a physician. It is customary to begin treatment with remedies that cause perspiration, and with the administration of purgatives.
As to the prevention of yellow fever, the principal requirement consists in carrying out extensive hygienic measures looking toward the complete extermination of the transmitting mosquito, the most important species being Stegonwia fasciata. All pools, cisterns, pot-holes, fountains, empty tin cans, etc., in which it is possible for the mosquito to breed, should be oiled or destroyed.
Particular attention must also be paid to preventing the mosquito from getting the disease, and thus making it liable to carry the infection. For this purpose all patients suffering from yellow fever should be protected by mosquito-netting, and all sick-rooms screened, so as to keep the mosquitoes out. People travelling in the tropics should always be supplied with mosquito-netting.
ZINC SALTS.—The salts of zinc are used to some extent in medicine. Soluble zinc salts combine with albumen, forming insoluble albuminates ; their action is therefore astringent, and in large quantities distinctly irrita ting. Of the salts sometimes used, the acetate, carbonate, chloride, oxide, and sulphate are the most common. The sulphate and acetate are used in solution as astringent applications in some diseases of the eye and in gonorrhoea. The sulphate is sometimes given in doses of ten to thirty grains as an emetic. Zinc carbonate and zinc oxide are largely used externally for various skin diseases, the ointment of oxide of zinc being a very soothing and slightly astringent salve. Zinc chloride is quite irritating, but is used in weak solutions for its astringent action. Stronger solutions are of use as caustics, and are sometimes utilised to destroy cancerous growths.
Poisoning by zinc sometimes occurs in men who are working with the metal. There is a sense of general discomfort and pain, followed by chills and sweats, with cough and soreness of the chest. The condition is probably due to inhaling the fumes of the zinc, and is very apt to recur frequently. Acute poisoning may occur from an over-dose of any of the salts. The symptoms are those of inflamed stomach and intestines. Albumen, as eggs or milk, should be given.
ACETANILID.—Egects: Loss of sensation, paralysis, heart depression, destructive changes in the blood, cyanosis, etc. Antidotes and Treatment: Apply heat externally (hot-water bottles, etc.), administer stimulants, give caffeine or strychnine to aid respiration, belladonna in small doses, and, if the skin be blue, oxygen by inhalation.