212 APPLIED BACTERIOLOGY 



that in filthy surroundings there is the more reason to fear 

 its ravages, and when once it has appeared it will be 

 expelled with greater difficulty. 



Accumulations of night-soil, rubbish, etc.,, should be 

 removed, and the places they occupied well cleansed. 

 Uncleanly premises should be thoroughly scrubbed and 

 limewashed, and proper ventilation insisted on. 



Pathogenesis. — The symptoms of Asiatic cholera are 

 intense and sudden fever and collapse, the face being 

 drawn and pinched, and the tongue cold. The urine is 

 suppressed, and the stools have the characteristic rice- 

 water appearance. Death may occur in so short a period 

 as twelve hours after taking the infection, or three hours 

 after the first symptoms are noticed. The incubation 

 period rarely exceeds two or three days. The symptoms 

 differ from those that occur in English cholera only in 

 intensity ; hence we are at present compelled to rely largely 

 on the bacteriological examination to decide whether a given 

 case is one of true Asiatic cholera or not. As a matter of 

 fact those cases of supposed cholera in which the ' comma ' 

 could not be found have very rarely proved infective. 



The experiments of Pettenkofer, Emmerich, Hasterlik, 

 and others, who have swallowed pure cultures of Koch's 

 ' comma ' in'^upport of their contention that cholera was 

 not caused by this organism, are held by some to throw 

 doubt on the ' specificity ' of the organism ; but it is more 

 probable that they escaped from ill effects by being in good 

 health, and having a normal acidity in their gastric juice. 

 It is probable that, had a larger number of people been 

 experimented on, the conclusions arrived at would have 

 been reversed. 



As already stated, experiments on animals by injection of 

 pure cultures are not productive of cholera unless some 

 special means are adopted to neutralise the acidity of the 



