CHOLERA. 185 



these researches, was able to isolate, especially from old cultures, substances 

 analogous to, or identical with, cadavarine, putrescine, and choline. Carrying 

 his experiments further, and cultivating the comma bacillus in media con- 

 taining cr'eatine, he produced a toxine or specific poisonous product which 

 produced, when injected into the animals, dyspnoea, muscular tremors, 

 cramp, and death. To this he gave the somewhat formidable name of 

 Methylguanidin. Carrying his observation still further, he succeeded in 

 separating from a precipitate obtained by the addition of a mercurial salt, 

 two other toxines, both of which appeared to be more or less characteristic 

 of the cholera growth. 



It will be noted that in all the experiments made, in which 

 the toxines were obtained even from pure cultures of 

 Koch's comma bacillus, the time required for their production 

 and the quantities separated are out of all proportion to what 

 occurs in actual cases of cholera, where, from the rapidity of 

 the course of the disease and the severity of the symptoms, 

 a large quantity of the poison must be developed in a very 

 short time. Most of the artificial experiments, however, 

 have bfeen made on different media (usually bouillon contain- 

 ing peptone) and under very different conditions from those 

 which obtain in an animal. In a series of investigations 

 carried out by Wood in Hueppe's laboratory, an attempt 

 was made to grow cultures under precisely those conditions 

 that are met with in the human intestine, with the result 

 that a very rapid toxine production, and an additional proof 

 of the bacillary origin of the cholera virus were obtained. 

 He took for his nutrient medium normal albumen, and thus 

 obtained the earlier products such as the albumoses that 

 occur in the breaking down of albuminoids. The presence 

 of these would of course account for the greater toxicity of 

 his cultures under such conditions. 



One of the earliest observations made by epidemiologists was 

 that one attack of cholera protects for a certain time and to a 

 certain degree against a second, and from this it was now 

 argued that it should be possible to obtain a system of pre- 

 ventive inoculation ; and Gamaleia, basing his work on what 

 was already known of preventive inoculation in other 

 diseases, commenced a series of experiments by means of 

 which he hoped to construct such a method of inoculation 

 against cholera. In this he was ultimately successful. He 

 found that if, from a culture of the vibrio Metscknikovi, an 

 organism almost identical with the comma bacillus, both 

 morphologically and physiologically, in beef broth, he took 



