Immunization, 253 



localities when the serum will be found to afford protection 

 for at least a short time. One advantage of this method lies 

 in the fact that it is also effective during the period of incuba- 

 tion, and that the inoculated animals do not become affected 

 and therefore do not spread the disease. 



Tokishige (1897) in Japan, and Pitchford & Theiler, as well as 

 Bordet & Danysz, during the invasion of the disease in South Africa, 

 aimed to increase the potency of the blood serum of recovered (so- 

 called salted) cattle, by injections of virulent blood. Kolle & Turner 

 injected at first 100 cc. subeutaneously in recovered animals after the 

 disappearance of the fever, then at intervals of several days increasing 

 quantities of virulent blood (the last time 5 liters in one injection). 

 After 3-4 pronounced reactions the animals produced a serum of which 

 20 cc. protected an animal weighing 300 kg. against a pathogenic 

 action of 1 cc. of virulent blood (for use in practice the blood serum 

 must have at least such a potency) . Animals which have not recovered 

 from rinderpest must be treated first with bile, or with blood serum 

 and blood, and only later with virulent blood. 



NicoUe & Adil-Bey observed in Constantinople, that animals which 

 recovered from rinderpest could not again be made sick by a sub- 

 cutaneous or intraperitoneal injection of a large quantity of virulent 

 blood (up to 10 liters), even when inoculated immediately after the 

 recovery. Accordingly recovered animals were, injected subeutaneously 

 at first with 4 liters of blobd, and later the quantity was increased. 

 Another method of these authors consists in the injection into the 

 abdominal cavity of an affected animal which already has diarrhea, 

 of 6 liters of a physiological salt solution containing peptone. Three 

 to six hours after the injection the animal is bled to death, and a 

 healthy animal is then injected subeutaneously with 2-3 liters of the 

 fluid collected from the abdominal cavity. The blood taken after 10, 

 15 or 20 days from this animal produces a potent serum; later the 

 animal again receives the abdominal fluid subeutaneously, and the 

 method is continued in this manner. Two weeks following the injection 

 of 4 liters of blood the animals produce a similarly potent serum, 

 no matter whether this quantity has been injected immediately after 

 the first opportunity or only in gradually increasing quantities. SJieep 

 are also adapted to the production of immune serum, the horse and 

 the goat however are not. By adding to the immune serum 14 to 

 1/2% of carbolic acid and keeping it in a dark place it remains potent 

 for four years (Theiler). 



The dose of the serum is 50-100 cc, according to the si7e of the animal. In 

 India the very susceptible mountain cattle are injected with 18 times larger doses 

 than are given to the cattle of the lowlands, and the quantity also depends on the 

 severity of the disease before the inoculations have been undertaken (Walker). 



According to the statistics of Turner, in 1897 33 herds on several farms, 

 with a total of 3318 cattle, of which 455 animals had already been affected, were 

 subjected to the serum treatment. Of these inoculated animals 455 died, while 

 2857 (86.1%) remained -healthy. In the English Egyptian Soudan Head .lost 2% 

 out of 7886 inoculated animals. The serum inoculation has been applied in China 

 to about 11,000 cattle, with very satisfactory results (Keylock). 



As it is sometimes difficult to obtain virulent blood, Eiidiger mqects cattle 

 intraperitoneally with 5 liters of a 1/2% potassium citrate solution. The animals 

 are slaughtered an hour later. The fluid thus injected proves very virulent and 

 when mixed with equal quantities of virulent blood produces a very effective and 

 a correspondingly cheaper material for the preliminary treatment of serum cattle. 



