266 OEIENTAL PLAGUE chap. 



use in assisting or in sharing in the protective action of 

 the Haffkine prophylactic. As a matter of fact, the 

 Indian Plague Commission deny (vol. v.) any action, 

 toxic or otherwise, of this fluid per se, and as far as can 

 be gathered from the questions put by some of the 

 members of the Commission to Professor Haffkine during 

 his examination before the Commission in Bombay, it 

 seems as if Professor Haffkine had been reproached for 

 having used broth culture (of course, sterilised) as plague 

 prophylactic, seeing that his cholera prophylactic was an 

 emulsion made from the growth of the cholera vibrio on 

 solid media. And, further, Calmette, in his Harben 

 Lectures (1900), assumes that all the prophylactic action 

 of a sterilised culture is and must necessarily be lodged 

 in the bacillary bodies themselves. Moreover, Professor 

 Haffkine himself has repeatedly pointed out (see his 

 evidence before the Plague Commission) the importance 

 of copious bacillary growth in his broth culture ; as a 

 matter of fact, the prophylactic dose recommended per 

 human individual has in practice been estimated according 

 to the amount of bacillary growth in the flask, the amount 

 of the dose being in inverse ratio to the turbidity, i.e. 

 amount of bacillary growth. 



While all these are facts of common knowledge, I 

 venture seriously to doubt the assumed inefncacy and 

 superfluity of the fluid part of the prophylactic. And 

 my doubts are based on good experimental grounds as 

 follows : — 



(a) Four half- grown rats were injected with filtrate 

 of the prophylactic, i.e. with the clear fluid siphoned off 

 from a tube (see above) and passed through a Pasteur - 

 Chamberland filter. Each rat received subcutaneously 



