208 MANUAL OF BACTERIOLOGY. 



per cent, solution requires three days to kill the bacillus of 

 typhoid fever. On account of its affinity for ammonia and 

 sulphides it is an efficient deodorizer for temporary use, but 

 cannot be relied upon to kill the bacteria producing the 

 noxious gases. 



Cupric Sulphate (Blue Vitriol}. This salt is quite an 

 efficient disinfectant. In a solution of 1-3000 the spirillum 

 of cholera is destroyed in ten minutes. A 5 per cent, solu- 

 tion will kill the typhoid bacillus in ten minutes. A solu- 

 tion of from 2 to 3 per cent, in strength can be relied upon 

 to destroy all pathogenic organisms that do not form spores. 



Zinc Sulphate. This salt is a very feeble disinfectant. 

 Pus cocci are not destroyed in two hours by a 20 per cent, 

 solution. As a deodorizer it has about the same value and 

 acts in the same way as ferrous sulphate. 



Zinc Chloride. A 2 per cent, solution will kill pus cocci 

 after an exposure of two hours. It is therefore a much 

 more powerful disinfectant than the sulphate. 



Disinfection of Dejecta and Urine. A 4 per cent, solu- 

 tion of calcic hypochlorite (chloride of lime) is most effi- 

 cient and rapid for this purpose. A convenient solution 

 contains 6 ounces of the salt to i gallon of water. The 

 excreta should be received in a suitable vessel and imme- 

 diately mixed with an equal bulk of the disinfectant. The 

 contents of the vessel should be allowed to stand for one 

 hour before emptying. A 20 per cent, milk of lime is just 

 as efficient, and possesses the advantage of cleanliness and 

 lack of odor. It should be used in the same quantity and 

 allowed to act for the same length of time. A 5 per cent, 

 solution of carbolic acid may be used, but should be allowed 

 to act for at least four hours. 



Disinfection of Sputum. The chemical disinfection of 

 tuberculous sputum is somewhat difficult on account of the 

 large amount of albumin in it and the fatty matter associated 



