CLINICAL EVIDENCE OF VALUE OF SERUM 429 



should be spread from one farm to another even where they are in 

 as close contact as were these two herds. 



This test serves to give an example of how the simultaneous 

 method of treatment is applied: 20 c.c. of serum and 2 c.c. of 

 virulent blood were injected into each one of the test animals. As 

 none of these animals afterward became sick it serves to show that 

 the serum was protective even against relatively large doses of the 

 pure culture virulent blood. The dose of serum given in this case 

 was relatively a little smaller than that usually given. 



In connection with certain arguments which have been made 

 against the simultaneous method of treatment in some parts 

 of the country, this experiment is also a source of intelligent ob- 

 servation and conclusion. Some men have made the argument 

 against the simultaneous methods of injection that by so doing 

 there was danger of infection of the premises by the discharges 

 of the animals so injected. This it was pointed out would result 

 in the establishment of an infectious feed yard, which would be 

 the source of infection to any healthy hogs which might afterward 

 be brought upon the place. 



Here we have in this experiment 3 animals injected by 

 the simultaneous method and left in constant association with 

 the healthy shoats, who were not so protected by either serum- 

 alone or serum-simultaneous injection. Yet neither of the check 

 pigs developed any symptoms of cholera. Evidently if there 

 was infection of this feed lot from the discharges of the simul- 

 taneously treated swine the disease would have made its appear- 

 ance in these untreated animals. 



It is also interesting to note that the simultaneously treated 

 hogs in this experiment did not show any bad effects from the 

 treatment, but continued to thrive and do well just as if nothing 

 had happened to them at all. When properly given there is ab- 

 solutely no danger from the simultaneous method of treatment 

 and its advantages are manifold. 



Here also we get an idea as to the class of cases in which serum 

 alone is indicated, and the class of cases in which the serum-simul- 

 taneous method is to be used. In the treatment of the animals 

 intended to be placed in the infected pens on Farm Number One 

 serum alone was used. You may ask why? Simply because in 



