50 KACTERIOLOGY 



take place between the spores of the anthrax bacilhis 

 and a solution of mercuric chloride, the result being 

 the apparent destruction of the living properties of the 

 spores by the formation of this third compound. In 

 these experiments it was shown that though this com- 

 bination had taken place, still it did not of necessity 

 imply the complete death of the protoplasm of the 

 spores, for if by proper means the combination of mer- 

 cury with their protoplasm was broken up, many of 

 the spores returned from their condition of apparent 

 death to that of life, with all their previous disease- 

 producing and cultural peculiarities. Geppert em])loyed 

 a solution of ammonium sulphide for the purpose of 

 destroying the combination of spore-protoplasm and 

 mercury. The mercury was precipitated from the pro- 

 toplasm as an insoluble sulphide, and the protoplasm 

 of the spores returned to its original condition. These 

 and other somewhat similar experiments have given au 

 entirely new impulse to the study of disinfectants, 

 and in the light shed by them many of our previ- 

 ously formed ideas concerning the action of disinfecting 

 agents must be modified. The process is not a cata- 

 lytic one — i.e., occurring simply as a result of the 

 presence of the disinfecting body which is not itself 

 destroyed in its process of destruction — but is, as said, a 

 definite chemical reaction which takes place within cer- 

 tain more or less fixed limits ; that is to say, with a given 

 amount of the disinfectant employed, just so much work, 

 expressed in terms of disinfection — destruction of bac- 

 teria — can be accomplished. 



Another point in favor of this view is the increased 

 energy of the reaction with elevation of temperature. 

 Just as in many other chemical phenomena, the intensity 



