_Bilious Typhoid of Egypt._—In 1851 Griesinger described a disease he called bilious typhoid of Egypt in which there was a sudden onset with marked chill and rise of temperature in four or five hours to 103° or 104°F. Rachialgia and bilious vomiting were marked. There was splenic enlargement. The temperature fell on the fourth or fifth day with at about this time the appearance of icterus. Relapses were the rule and the mortality was very high. Bone pains, especially about the knee, were common and severe. This disease is now considered a relapsing fever. It is this disease which affected the troops of Napoleon in Egypt and which was thought by some authorities to have been yellow fever. Others think it may have been epidemic jaundice. PROGNOSIS This is bad with advancing years and possible lesions of liver or kidneys. It is difficult to make a statement as to the average mortality. Thus, in the epidemic of 1853, one of the most virulent that ever visited New Orleans, the mortality was estimated at 85%, while that of 1897, one of the mildest epidemics on record, only gave a mortality of ½%. As a general rule the earlier in the year an epidemic starts the more virulent the disease; thus the 1853 epidemic, just referred to, started in May. High temperatures and excessive albuminuria, as well as early appearance of jaundice, are bad signs. The mortality may be considered as averaging about 20%. PROPHYLAXIS AND TREATMENT =Prophylaxis.=—By screening a patient during the first three days of the disease we prevent the infection of _Stegomyia_ (_Aedes_). It must be remembered that this mosquito not only breeds near human habitations but that it tends to remain in the same room where it has been feeding. Consequently we should use sulphur fumigations or Giemsa’s spray or killing by hand to destroy insects. The larvae breed by preference in old tin cans near the house door. To kill these one should empty every old receptacle of water, and oil or cover other collections of water. All receptacles used for collecting and storing water draining from roofs should be carefully screened with fine copper wire gauze. Of particular importance is it to treat every suspicious case as it if were one of yellow fever and screen the patient as well as destroy any mosquitoes in the room or house occupied by such patient. Noguchi reports success in prophylaxis by the injection of 2 cc. of a killed culture of _Leptospira icteroides_. Immunity is not conferred until after the tenth day. He notes that among 3607 persons vaccinated in Salvador there were no cases of yellow fever while among the unvaccinated 181 cases occurred. Killed cultures of _Leptospira icteroides_ were first used for protective inoculation in 1918 when 427 vaccinations were carried out.