$ xiii.] Asiatic cholera. 165 



still remains unexplained ; for instance, the immunity enjoyed 

 by certain localities, the fact that an epidemic of the disease in 

 Europe ceases entirely after the lapse of a certain time, and 

 some other points. But it is no objection to well-established 

 explanations, either here or in any other domain of human 

 knowledge, that this or that point is still unexplained. 



Other objections, current certainly till quite recent times, were 

 aimed directly at the real character of Koch's Spirillum as the 

 specific contagium of cholera. So far as they rested on the 

 failure of attempts to communicate the infection with the pure 

 Spirillum, they are set aside by the positive results now before 

 us of similar attempts, supposing these to be trustworthy. On 

 the other hand, they denied that Koch's organism was present 

 exclusively in cases of Asiatic cholera. Finkler and Prior dis- 

 covered a Spirillum extremely like it in the affection of the bowels 

 known as indigenous cholera, cholera nostras. Lewis and, after 

 him, Klein pointed to the comma-spirillum of the mucus of 

 the mouth (see page 120 and Fig. 1 6, d), which is common in 

 healthy human beings, and when seen in single specimens is also 

 so like Koch's Spirillum that it might be considered to be identical. 

 But further investigation has now removed all doubt concerning 

 certain trustworthy distinctions, which come to light especially in 

 cultures on a large scale, between these and other similar forms 

 which cannot be enumerated here and Koch's organism; all 

 attempts even to cultivate Lewis' Spirillum from the mouth as a 

 saprophyte have as yet been attended with no positive result. 

 Whether Finkler's and Prior's Spirillum may be the specific 

 exciting cause of some other disease than Asiatic cholera cannot 

 be considered here. 



The most thorough-going objection, however, is that brought 

 forward by Emmerich and supported by H. Buchner; these 

 observers maintain that another than Koch's Bacterium is the 

 specific contagium of cholera a short non-motile rod-bac- 

 terium, which figures in literature under the provisional name 

 of the Naples Bacillus. 



