ESSAYS ON BACTERIOLOGY. 61 



theria. Already it is reported that clinical use has 

 been made of this discovery in actually curing some 

 six or seven cases of tetanus in men. The first ex- 

 periments in this direction were made by transfusion 

 of the whole blood. Subsequently it was found that 

 the protecting properties resided not in the corpuscles 

 but in the serum. 



It is to be noted here that these defensive proteids 

 are not general in their action; that is, serum, or a de- 

 fensive proteid derived from it, which will protect 

 against one disease will not necessarily protect against 

 others. We cannot, therefore, at present entertain 

 the idea of discovering a universal bactericidal agent 

 of blood serum, sufficient at least for use as a general 

 protective. Hankin suggests a classification of these 

 defensive proteids into two groups: first, those exist- 

 ing naturally in animals, and these he calls sozins; 

 second, those existing in animals artificially made im- 

 mijjie, which he calls phyloxins. For sub-classes he 

 suggests the prefixes mico- and toxo- to indicate so- 

 zins or phyloxins which destroy bacteria or which de- 

 stroy toxins. Emmerich, in summing up his re- 

 searches, claims to have established two important 

 principles: first, that the caLise of artificial immunity 

 is an anti-bacterial substance which is not injurious to 

 the body; and second, that the protective fluid for 

 one class of animals may be applied against that par- 

 ticular disease in other classes of animals. For in- 

 stance, that the fluid from protected rabbity could be 



