IX 



bouillon has been used, it will be seen, that it is quite 

 impossible to ascertain to which group, typhoid or coli, 

 the abo\ r e named bacilli belong, as their power to pro- 

 duce a colour change is tinder these circumstances 

 nearly the same. The difference in colour produced by 

 the true B. typhosus and B. coli employed for these 

 experiments is also so slight, that it would be quite 

 impossible to distinguish them in this way. 



Quite different results are obtained from the same 

 strains of bacilli in 3% lactose neutral red bouillon 

 (Table XXIII). From column neutral, 0.5 and 1 NaOH 

 it is thus seen that B. typhosus and the 2 bacilli of the 

 typhoid group produce a yellow colour as a final result. 



TABLE XXIII. (3% lactose bouillon). 





- 34 



