SKIN-DISINFECTION. 257 



In making the above experiments it must be remem- 

 bered that the strictest eare is necessary in order to pre- 

 vent the access of germs from without into our media. 

 The hand upon which the experiment is being per- 

 formed must be held away from the body and must not 

 touch any object not concerned in the experiment. The 

 scraping should be done with the point of a knife which 

 has been sterilized in the flame and allowed to cool 

 down. The scrapings may be transferred directly from 

 the knife-point to the gelatin by means of a sterilized 

 platinum wire loop. 



The brush used should be thoroughly cleansed and 

 always kept in 1 : 1000 solution of corrosive sublimate. 

 It should be washed in hot water before using. 



