ELEVENTH ANNUAL YEAR BOOK— PART X 563 



a high temperature. If the serum is now injected into a hog without 

 subsequent infection, the immune bodi'es would, in the process of metabol- 

 ism, be eliminated from the body within a few weeks or months. If 

 the hog became exposed at about the same time by artificial inocula- 

 tion, or natural infection, the immune bodi'es would unite with the 

 receptors of the virus, and through the medium of these immune bodies, 

 the complement which is found in all normal serum, would destroy the 

 virus. If the hog had become infected sometime previous so that the 

 virus was present in considerable quantities, the amboceptors or immune 

 bodies which would be contained in an ordinary dose of serum would be 

 insufficient to prepare all of the virus for the action of the complement. 

 Consequently, the use of serum would have very little, if any, effect, upon 

 the course of the disease in already affected animals. If the serum is 

 of low potency, that i's, containing few immjune bodies, and the virus very 

 virulent in the simultaneous method, we would expect unfavorable 

 results. The serum simultaneous method would not be indicated where 

 the opportunities for infection in the natural way are sufficient; and 

 when used, the resistance of the animal, the virulency of the virus, and 

 the potency of the serum should all receive due consideration. 



IMMUNE HOGS. 



There are two methods by which they can be had. Firstly, by the 

 serum alone method, and exposure to the disease by allowing the subject 

 to associate with hogs affected with cholera after giving him the pre- 

 scribed dose of serum depending upon his weight. Secondly, the serum 

 simultaneous method. It is the same part as the serum alone method 

 but consists in artificially exposing the subject by introducing two cubic 

 centimeters of blood in the opposite thigh, not necessitating him to as- 

 sociate with cholera hogs. The latter method is faster. We aim to have 

 a supply of immunes on hand at all times for our serum tests. 



HYPERIMMUNING. 



Hog cholera serum is nothing more or less than the defibrinated blood 

 of hyperimmunes with proper antiseptics added for preserving it and con- 

 sists of a saturated solution of antibodies to antagonize the germ of 

 hog cholera. There are four ways or methods of transforming an im- 

 mune into a hyperimmune. 



1. The quick subcutaneous method. 



2. The slow subcutaneous method. 



3. The intraperitoneal method. 



4. The intravenous method. 



THE QUICK SUBCUTANEOUS METHOD. 



This method is often used and consists of introducing subcutaneously 

 in the region of the abdomen ten cubic centimeters of virulent blood to 

 the pound of live weight of the immune. For example; an immune 

 weighing 150 pounds should receive fifteen hundred cubic centimeters 

 of virulent blood at one dose to hyperimmunize him by this method. This 

 method often causes leakage through the needle wounds owing to the 



