DISINFECTION AND DISINFECTANTS. 221 



higher the temperature, the more is their disinfecting 

 power increased. In this way substances of feeble dis- 

 infecting powers may often be used to advantage. The 

 value of heating a disinfectant is well illustrated by com- 

 paring the action of carbolic acid upon the anthrax bacil- 

 lus and its spores. Anthrax bacilli are killed in ten sec- 

 onds by a one per cent solution of carbolic acid, yet its 

 spores can live a month in a five percent solution. But 

 if the temperature of a five per cent solution of the same 

 acid is raised to 75° C. (134.6° F.), they are killed in 

 three minutes. In all disinfection, therefore, hot solu- 

 tions should be used. 



DISINFECTING SOLUTIONS. 



Perhaps the commonest disinfectant used 

 Bichloride is bichloride of mercury (corrosive subli- 

 OF Mercury, mate). It is a powerful germicide, even in 



weak solutions. It has several serious 

 drawbacks, however, which limit its usefulness ; among 

 these is the fact that it is a corrosive poison; that its 

 solutions attack practically every metal; and that it 

 unites with albuminous matter. For the last reason it is 

 not to be used as a disinfectant for the disinfection of 

 sputum, feces, and discharges containing albumin, 

 such as pus. For washing floors, walls, and other sur- 

 faces, a hot solution (i-iooo) is as efficient as any other 

 disinfectant. For ordinary purposes the i-iooo solu- 

 tion is the strength employed. This can be prepared 



