VACCINE-THERAPY 71 



the ordinary course slough out, but in this case is so 

 imprisoned that separation cannot take place. Needless 

 to add, a vaccine could never effect a cure until the dead 

 slough had been removed, and vaccine-therapy should not 

 be condemned because it failed in what it was never 

 intended to do — i.e., remove a dead slough. 



Vaccines are divided into two great classes — stock 

 vaccines and autogenous vaccines. A stock vaccine is 

 prepared from bacteria of the same species, but derived 

 from a different source, and kept in the laboratory for 

 emergency and general purposes. An autogenous vaccine 

 is derived from cultures of the actual bacterium or its strain, 

 already producing the infection in the animal. Again, 

 vaccines are further subdivided into monovalent vaccines 

 and polyvalent vaccines, the former being derived from a 

 single strain of a particular bacterium, and the latter from 

 several strains and races. And, lastly, we have prophylactic 

 and curative vaccines, the former composed of devitalized 

 bacteria, which are injected into an animal whose species 

 are susceptible to the ravages of the bacterium; and by so 

 doing that animal becomes partly or completely immune 

 to the disease - producing influences of that specific 

 bacterium. The latter, as the term implies, are utilized in 

 rousing the bactericidal elements of the animal body to 

 overcome the invading organisms and their death-producing 

 influences. It is only reasonable to suppose that an auto- 

 genous vaccine is to be preferred to a stock one, and this 

 is borne out in practice with few exceptions; when one is 

 dealing with an acute disease, such as pneumonia, a stock 

 vaccine should be administered at the outset, inasmuch as 

 it takes time to isolate the causative organism and prepare 

 an autogenous vaccine, for during the time spent in prepara- 

 tion the patient may be getting rapidly worse. To prepare 

 an autogenous vaccine, we take the morbid material from 

 the patient, with careful aseptic precautions to prevent 

 outside contamination ; and, as this is an important point, it 

 is perhaps as well to record briefly the method of so doing 



