414 DISEASES OF SWINE 



body of the animal of the hog-cholera germs in sufficient numbers 

 to set up a severe attack upon the body. 



On this account, if serum alone is used where hog-cholera virus 

 is already present in the body of the animal, as in those cases that 

 show a high temperature, the protection which results proves to be 

 of the permanent kind. By the time the effects of the serum have 

 worn off the body is manufacturing germ protectors for itself, and 

 there will always be an army of these defenders ready to stop any 

 further attack of this disease which might occur later in the life 

 of the animal. 



(8) If virus alone were injected into the body of an animal it 

 would produce death of the hog within five to fifteen days, depending 

 upon the amount of virus which was used and the strength of this 

 virus. 



(9) When virus is injected into the animal, and a dose of serum 

 is also injected at the same time, the fatal outcome is prevented by 

 the presence of the large amount of germ destroyers that are con- 

 tained in the serum. These germ fighters protect the cells of the 

 animal body against the attack of the germs and the poisons which 

 they form, and this gives the cells a chance to get busy and learn 

 how to make these germ-destroying bodies. This is the underlying 

 basis of the double method of treatment. 



(10) Where the double method of treatment is used the cells of 

 the body are taught how to make the germ-destroying bodies, and 

 once they have learned how, they never neglect to keep a large 

 supply of these germ fighters in the blood. The result is that the 

 animal remains protected for life. 



(11) There is absolutely no danger in using the double method 

 of treatment if the serum used be of first-class quahty. With a 

 good serum there is no chance in the world for the germs to cause 

 an outbreak of cholera, because their action is checked by the anti- 

 bodies of the serum before they have had an opportunity to produce 

 any harmful effect. 



(12) The argument that the use of the double method of treat- 

 ment results in the infection of the feed lots in which the animals 

 so treated are kept does not appear to be proved. On the other 

 hand, the outcome of experiments so far made along this fine would 

 seem to prove just the opposite to be the case. The virus that is 



