VACCINATING INJECTION 6a 



intravenous injections were carried out twice, thie 

 first injection being nearly ten times weaker than 

 the second. The interval between the two injections 

 was, at the beginning of our experiments, fixed at 

 twenty-four hours; later, we reduced it at first to 

 three hours, then to one hour, and finally to ten 

 minutes. An interesting fact is that the reaction 

 that follows the second injection of bacteria, however 

 massive, is always relatively weak. Thus, six hours 

 after the second injection, made with a very large 

 quantity of bacteria, the temperature reaction was 

 not perceptibly greater than six hours after the first 

 injection, made with a dose of bacteria ten times less. 

 The temperature the next day was almost always 

 normal, even when the quantities of culture injected 

 intravenously were extremely large. 



The method of small doses has consequently been 

 applied by Briot and Dopter^ in the immunisation of 

 horses against meningococci. " The contrast," say 

 these authors, " is surprising between the results of 

 these injections practised twice and those in which 

 the emulsion has been injected entirely at the first 

 trial. Not only have these horses been able to 

 tolerate with impunity the dose injected the previous 

 week, but, moreover, progressive^ increasing doses. 



M. Ciuca has utilised the method of small doses in 

 horses intended for the preparation of antistrepto- 

 coccic and anti dysenteric sera. At our advice, he 

 introduced, ten minutes before the injection of the 

 total dose of virus, a tenth or a twentieth of the dose. 

 Before the use of this method three horses out of five 

 succumbed to anaphylactic symptoms in the space 

 of seven to ten minutes. Since M. Ciuca^ employed 

 the process in question, he has never had any deaths. 

 According to his statement, not only are the horses 



^ Comptes rend. Soc. de Biol., Ixix., p. 174, 1910. 

 2 Zeitschr.f. Immunitdtsf., t. xix., p. 174. 



