ASIATIC CHOLERA. 55 



of the posterior extremities, repeated vomiting, and cold head and 

 extremities. After two hours these symptoms began to abate, and 

 after twenty-four hours recovery seemed complete. Control experi- 

 ments with like amounts of uninfected beef tea gave negative results. 

 The cultures used were three days old when sterilized. Older cul- 

 tures seemed less poisonous, and a high or prolonged heat in sterili- 

 zation decreased the toxicity of the fluid ; therefore, Cantani concludes 

 that the poisonous principle is volatile, but the effect of high or pro- 

 longed heat in diminishing the toxicity was more probably due to 

 destructive action on the toxin. The same observer found that the 

 blood of those sick with cholera is acid ; this has been confirmed by 

 Strauss on examining the blood directly after death, and Ahrend 

 found lactic acid in the strongly acid urine of a cholera patient. 



Nicati and Rietsch killed dogs by injecting intravenously cultures 

 from which all the germs had been removed by filtration, and they 

 also obtained from old bouillon-pepton cultures a poisonous base. 

 Van Ermengem also found that cultures after filtration through a 

 Chamberland filter are poisonous. 



Klebs studied the cholera toxin in the following manner : Cul- 

 tures in fish preparations were acidified, filtered ; the filtrate evapo- 

 rated on the water-bath ; the residue taken up with alcohol and pre- 

 cipitated with platinum chlorid. The platinum was removed with 

 hydrogen sulphid and the crystalline residue obtained on evaporation 

 was dissolved in water and injected into rabbits intravenously. 

 Muscular contractions were induced, and death followed in one ani- 

 mal, which, in addition to the above treatment, received an injection 

 of a non-sterilized culture. In the latter case the epithelium of the 

 uriniferous tubules was found to be extensively calcified. Klebs 

 believes this change in the kidney to be induced by the chemical 

 poison, and he explains the symptoms of the disease as follows : 

 The cyanosis is a consequence of the arterial contraction, the first 

 effect of the poison. The muscular contractions also result from the 

 action of the toxin. The serous exudate of the intestines follows 

 upon epithelial necrosis. Anuria and the subsequent symptoms 

 appear when the formation and absorption of the poison become 

 greatest. 



Hueppe states that the severe symptoms of cholera can be ex- 

 plained only on the supposition that the bacilli produce a chemical 

 poison, which resembles muscarin in its action. 



Villiers isolated by the Stas-Otto method from two bodies dead 

 from cholera a poisonous base which was liquid, pungent to the taste, 

 and possessed the odor of hawthorn. It was strongly alkaline, and 

 gave precipitates with the general alkaloidal reagents. From one to 

 two milligrammes of this substance injected into frogs caused de- 

 creased activity of the heart, violent trembling, and death. The 

 heart was found in diastole and full of blood, and the brain slightly 



