70 VACCINE AND SEEUM THERAPY 



has some power of passive immunisation when in- 

 jected into another animal. Injections of the bile 

 from animals having had the disease has been ad- 

 vocated by Koch, and extensively practised in South 

 Africa, with good results. Immunisation by the use of 

 hyperimmunised serum, prepared from animals which 

 have recovered from the disease, has been developed 

 by KoUe and Turner. Twenty c.c. of this serum 

 should protect an animal against infection of 1 c.c. of 

 virulent blood. An injection of 50 to 100 c.c. of this 

 serum will protect an animal against infection for 

 a period of two to four months usually. A more 

 permanent immunity may be established by the use 

 of the serum simultaneous method. The animal is 

 injected on one side with 8 to 25 c.c. immune serum 

 and on the other with 1 c.c. of virulent blood. Some 

 animals react by a distinct fever, others show no 

 effect ; the latter are rendered immune for several 

 months only, while the former for a much longer 

 period. 



Pleuro- Pneumonia Contag-iosa of Bovines. — This 

 is a contagious disease of cattle and other bovines. 

 The disease is scheduled in the British Isles. It is 

 very prevalent in Europe and other countries. 



Etiologij. — The causal organism is doubtless a 

 bacterium that is just at the limit of visibility. In 

 suitable fluids it may be observed, under very high 

 power of microscope, as a tiny motile point. 



Immunity. — Recovery from the disease results in 



