52 HEAT. 



as we have just learned, is always more or less question- 

 able, especially in those cases in which the substance to 

 be disinfected is of an albuminous nature. With the in- 

 troduction of such substances into the sublimate solution 

 the mercury is quickly precipitated by the albumin and 

 its disinfecting properties may be entirely destroyed ; 

 we may in a very short time have little else than water 

 containing a precipitate of albumin and mercury, in so 

 far as its value as a disinfectant is concerned. 



In the laboratory, then, heat is the surest agent to 

 employ. All tissues containing infectious organisms 

 should be burned, and all cloths, test-tubes, flasks, and 

 dishes should be boiled in 2 per cent, soda solution for 

 fifteen to twenty minutes, or placed in the steam sterilizer 

 for at least half an hour. 



Intestinal evacuations may best be disinfected with 

 milk of lime, a mixture composed of lime in solution and 

 in suspension. This should be thoroughly mixed with 

 the evacuations until the mass reacts distinctly alkaline, 

 and should remain in contact with the infective sub- 

 stance for several hours. 



Sputum in which tubercle bacilli are present, as well 

 as the vessel containing it, must be boiled in soda solu- 

 tion for fifteen minutes or steamed in the sterilizer for 

 at least half an hour. 



On the whole, for the laboratory we should as yet 

 rely more upon the destructive properties of heat than 

 upon that of chemical agents. 



From what has been said, the absurdity of sprinkling 

 about, here and there, a little carbolic acid or in placing 

 about apartments in which infectious diseases are in 

 progress little vessels of carbolic acid, must be plain. 

 The disinfection of water-closets and cesspools by allow- 



