Toxic Products 503 



does not live longer than twenty or thirty days in fecal 

 matter, and often disappears in from one to three days. 

 The organism is very susceptible to the influence of carbolic 

 acid, bichlorid of mercury, and other germicides, and is 

 also destroyed by acids. Hashimoto * found that it could 

 not live longer than fifteen minutes in vinegar containing 

 2.2-3.2 per cent, of acetic acid. 



According to Frankel, in eight weeks the organisms in 

 the liquefied cultures all die, and cannot be transplanted. 

 Kitasato, however, has found them living and active on 

 agar-agar after from ten to thirty days, and Koch was 

 able to demonstrate their vitality after two years. 



This low vital resistance of the microbe is very fortunate, 

 for it enables us to establish satisfactory quarantine for the 

 prevention of the spread of the disease. Excreta, soiled 

 clothing, etc., are readily rendered harmless by the proper 

 use of disinfectants. Water and food are rendered innocu- 

 ous by boiling or cooking. Vessels may be disinfected by 

 thorough washing with jets of boiling water discharged 

 through a hose connected with a boiler, and baggage can 

 be sterilized by superheated steam. 



Metabolic Products. Indol is one of the characteristic 

 metabolic products of the cholera spirillum. As the cholera 

 organisms also produce nitrites, all that is necessary to 

 demonstrate its presence in a colorless solution is to add a 

 drop or two of chemically pure sulphuric acid, when the 

 well-known reddish color will appear. 



The organism also produces acid in milk and other 

 media. Bitter has also shown that the cholera organism 

 produces a peptonizing and probably also a diastatic 

 ferment. 



Toxic Products. Rietsch thinks the intestinal changes 

 depend upon the action of the peptonizing ferment. Can- 

 tani, Nicati and Rietsch, Van Brmengem, Klebs, and others 

 found toxic effects from cultures administered to dogs 

 and other animals. Several toxic metabolic products of 

 the spirilla have been isolated. Brieger, f Brieger and 

 Frankel, { Gamaleia, Sobernheim, || and Villiers have 



* 'Kwai Med. Jour.," Tokyo, 1893. 



t 'Berliner klin. Wochenschrift," 1887, p. 817. 



t ' Untersuchungen iiber die Bakteriengifte," etc., Berlin, 1890. 



'Archiv de Med. exp.," iv, No. 2. 



|| 'Zeitschrift fur Hygiene," xiv, 145, 1893. 



