VARIOUS CHEMICAL DISINFECTANTS 59 



or of soda are extremely valuable for certain purposes 

 in domestic sanitation, and scientific researches fully 

 justify the cleansing methods with these agents which 

 have long been popular with good housewives. A 

 hot solution of caustic soda or potash in the propor- 

 tion of one part to two hundred of water will quickly 

 destroy the germs of cholera, of typhoid fever, of 

 diphtheria, or of glanders. 



Caustic lime is also an excellent disinfectant and 

 has the advantage of being comparatively cheap. For 

 this reason it is one of the best agents for the disinfec- 

 tion of masses of filth in vaults or cesspools and upon 

 the surface of the ground. Milk of lime, made by 

 slaking fresh quicklime with water and mixing the 

 resulting hydrate of lime with eight parts of water 

 may be used for this purpose and also for the dis- 

 infection of liquid excreta in the sick-room. Lime 

 wash applied to surfaces is a reliable disinfectant, as 

 has been proved by experiment, thus giving scientific 

 confirmation of the value of a method which has 

 gained popular favour as a result of experience that 

 is, of the sanitary value of whitewash freely and fre- 

 quently applied to outbuildings, cellar walls, etc. 



Various coal-tar products have been proved to be 

 valuable germicides, and on account of their compar- 

 ative cheapness have been largely used in practical 

 disinfection. Among these the most useful are 



