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CHAP. 



nating power, but, on the contrary, seemed to destroy it, 

 though it reappeared after several further subcutaneous 

 injections. Another important fact is brought to light in 

 this as in experiment No. 7, viz. the distinct agglutina- 

 tion possessed by the blood serum nearly two months after 

 the last injection. 



I shall have to reconsider later on other points con- 

 cerning these animals, but at present I proceed with the 

 examination by further experiments of the agglutination 

 phenomenon. 



III. — Experiments in Agglutination after Injection 

 of Filtrate of Haffkine's Prophylactic 



9. In this experiment two half-grown guinea-pigs were 

 injected subcutaneously with the clear filtrate of Haffkine's 

 prophylactic. This was obtained by simply opening some 

 of the sealed tubes in which the prophylactic had been 

 preserved, decanting the clear fluid and passing it through 

 a Pasteur-Chamberland filter. The filtrate was of course 

 perfectly limpid. 



Guinea-pigs Nos. 9 and 10 (half-grown) were injected 

 subcutaneously, each receiving 10 cc. of the above fil- 

 trate : — 



