BACTERIOLOGY IN A NUTSHELL. 



Animals 



Experimented 



Upon. 



Protection. 



Testing. 



ing in broth, bouillon or other culture media. 

 After the bacteria have remained in the culture 

 media for a stated period their poison per- 

 meates it. Some of the bouillon is then taken 

 and injected into the chosen animal (horses, 

 goatSi guinea pigs, rabbits, etc., are a,ll experi- 

 mented upon. The horse is preferred for the 

 development of diphtheria antitoxin), with a 

 special syringe, in very small doses at first 

 which are gradually increased until the animal 

 ceases to exhibit any symptoms of the disease, 

 the poison of which has been used for the in- 

 jections. Then he is said to be immune or 

 protected from that particular disease. Some 

 of the blood of this immunized animal is then 

 procured and allowedtocoagulate and the serum 

 or fluid part is injected into other animals or 

 into members of the human family, in the same 

 way in which it was used in the first instance, 

 until they too become immune from that specific 

 disease for a longer or shorter period. 



Before using the blood serum of an im- 

 munized animal on the human subject it is 

 tested in another of the lower animals for the 

 purpose of ascertaining its protecting power. 

 If it stands the test, it is put up in small tubes 

 sterilized and tighty sealed until required for 

 use. Diphtheria, tuberculosis, tetanus, septicemi;^ 

 and other diseases are treated by antitoxin 

 inoculations, Th^ mortality rate in diphtheria, 



