258 MANUAL OF BACTERIOLOGY. 



the pure oil cannot be used. The use of powdered mustard, 

 in the autopsy-room will remove the foul odor from the hands 

 more rapidly and completely than any other means. 



Coal Oil or Petroleum. While the disinfectant value of this 

 substance is slight, its use in destroying the larvae of insects, 

 such as the mosquito, has given it an important position in 

 preventing the spread of malaria and yellow fever. A small 

 amount poured on a stagnant pool rapidly spreads over the 

 surface and effectually destroys such larvae. 



Ferrous Sulphate (Copperas). This salt has been much used, 

 but possesses only feeble disinfectant powers. A 3 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 effi- 

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

 cholera is destroyed in ten minutes. A 5 per cent, solution will 

 kill the typhoid bacillus in ten minutes. A solution 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 the Mouth. Wadsworth* found that for 

 mouth disinfection in pneumonia, of all the antiseptics in com- 

 mon use alcohol alone proved efficient when tested on the pneu- 

 mococcus He tested a long list of various preparations, but 

 these were all counteracted by the mucus in the mouth. 



*Journ. Infectious Diseases. Vol. III., p. 774. 



