There is considerable thirst and vomiting, and in bad cases the vomit becomes black, the colour being due to the presence of blood. (In ordinary malaria the vomit is yellow, or in severe cases, such as blackwater fever, it may be of a bright or dark-green colour.) In yellow fever, jaundice is developed about the third day, and tends to increase, whilst in blackwater fever it comes on very early and soon begins to abate. An important diagnostic sign in yellow fever is found in the fact that the pulse does not increase in rapidity as the temperature rises. _Prophylaxis._—Avoid being bitten by mosquitoes, employing the methods mentioned on pages 206, 207. It must be remembered that _Stegomyia fasciata_, unlike the anopheline mosquitoes, bites during the day, and therefore it is more difficult to avoid its unwelcome attentions. It usually breeds in the neighbourhood of houses, being what may be called a domestic mosquito; and it is of the greatest importance to abolish all potential breeding places or to protect them from the mosquito. Practically any vessel holding water may become a nursery for Stegomyia, and it is remarkable in what small quantities of water this mosquito will lay her eggs. Patients suffering from the disease must be isolated and kept under a mosquito net or in a mosquito-proof chamber, in order to prevent them from infecting mosquitoes, which they are capable of doing in the early part of the disease. _Treatment._—Open the bowels well by means of calomel, six grains, followed by a saline purge and hot-water enema. Some prefer castor oil in large doses. Give ten grains of bicarbonate of soda three times a day. Give cooling drinks, such as fruit salt. Make the skin act. Apply hot fomentations to the back and mustard leaves to the pit of the stomach. The question of feeding is very important. During the first two or three days of the fever the patient is better without any food at all. As he recovers his appetite returns, and great care must be exercised about gratifying it. Only the plainest foods in very small quantities should be permitted, the amounts being gradually increased, as otherwise relapses may occur. Stimulants are usually required in the later stages of the fever, but they must be carefully employed as they may tend to increase the vomiting. It is possible that the discovery of the parasite may lead to new and more efficient methods of treating the disease. MEDICINES, MEDICAL APPLIANCES, ETC. WEIGHTS AND MEASURES. _Solids._ A Grain Symbol Gr. 20 Grains 1 Scruple { weights now ” ℈ 60 Grains 1 Drachm { rarely used ” ℨ 437.5 Grains 1 Ounce ” ℥ 16 Ounces 1 Pound ” ℔ _Note._—An ounce weighs not 8 but rather under 7½ drachms. 1 Gramme about 15½ grains. 1 Kilogramme ” 2 lbs. 3¼ ozs. _Liquids._