TYPHUS FEVER. — YELLOW FEVER. 259 



found in the urine, sweat, or saliva. They have not been cultivated 

 artificially on any nutrient media. Monkeys have been successfully 

 inoculated with blood containing the spirilla by Koch, Carter and 

 Soudakewitch ; and Koch found the spirilla in the vessels of the 

 brain, liver, and kidneys, after death. According to Soudakewitch 

 a fatal result is produced in monkeys if the spleen is removed, 

 and the spirilla are found in great numbers in the blood ; but if 

 the spleen is not excised the spirilla rapidly disappear, and recovery 

 follows. Munch and Motschutkowsky transferred blood containing 

 the spirilla to healthy persons, and produced typical relapsing fever. 



Typhus Fever. 



Typhus fever is a highly contagious disease, which lasts for two 

 or three weeks, and produces a measly eruption. Like the plague, 

 it is intimately associated with overcrowding and filth, and is liable to 

 occur where these conditions exist in cities, in armies, and in prisons. 

 The virus produces profound changes in the blood, and after death 

 the internal organs are found to be congested, especially the lungs, 

 which are very friable. The spleen is softened and often enlarged, 

 and the' blood is dark and imperfectly coagulated. 



The virus is dissipated by fresh air. It is given off by the 

 breath of patients, and possibly from the skin. It clings to the 

 clothes of patients, and the disease may be conveyed by their agency. 

 One attack, as a rule, confers immunity. Some persons are naturally 

 insusceptible, failing to contx'act the disease though daily exposed to 

 it. Hlava has described a bacterium which he believes to be the 

 specific micro-organism. Thoinot and Calmette found the same 

 bacterium with others, but there was no particular micro-organism 

 constantly present. There can be little' doubt that the nature of 

 the contagium is unknown. 



Stamping-out System. — Sanitary precautions, and especially 

 the operation of the Public Health Acts in relation to lodging- 

 houses, prisons, and the better housing of the working classes, have 

 been instrumental in almost completely stamping out the disease in 

 this country. 



Yellow Fever. 



Yellow fever is a disease of tropical climates, characterised by 

 abdominal tenderness, hemorrhagic vomiting (black- vomit), and 

 jaundice. The disease may end fatally, or recovery occur in about 

 two or three weeks. It is especially prevalent in the West Indies 

 and in parts of North and South America. 



