292 



A MANUAL OF BACTERIOLOGY 



1 part, water 3 parts, with 1 per cent, of carbohydrate or other 

 substance, tinged with litmus and sterilised in the steamer on three 

 consecutive days. Graham-Smith * gives the following Table of 

 fermentation tests : 



C = coagulation ; = no coagulation ; A = acid ; = no reac- 

 tion. Slight variations were occasionally noted : for example, four 

 out of twenty diphtheria bacilli gave no acid with lactose, and the 

 amount of acid production and of coagulation was somewhat variable. 



Clinical Diagnosis 



(A) In man and animals : I. In some cases the diphtheria 

 bacillus can be identified in the membrane or discharge, and the 

 diagnosis established thereby. 



Films are made with the exudation, or with a fragment of the 

 membrane teased up as finely as possible on a slide, a droplet of 

 water being added if necessary. One of these films should be 



1 Journ. of Hygiene, vol. vi, 1906, p. 286. 



