l888.] NEW-YORK MICROSCOPICAL SOCIETY. 15 



the last fifty years. It may be taken as an established fact, 

 that its diffusion over the world from India results from human 

 intercourse. During its first entry into Russia, and its spread 

 through northern Europe in a north-westerly direction, it was 

 supposed by many physicians to owe its dissemination to some 

 mysterious atmospheric, or telluric agent. But its slow and 

 halting progress rendered such a view improbable. A remark- 

 able circumstance regarding Cholera is, that although it has 

 spread to almost every part of the world, and has sometimes 

 prevailed under widely different thermometric and other con- 

 ditions, it seems to be capable of establishing itself permanently 

 only in India, and in a particular region of that country. 



With regard to the mode of diffusion of Cholera, it but seldom 

 passes from a sick person to one who nurses him. It is believed, 

 and I might say pretty conclusively demonstrated, that the con- 

 tagion of Cholera escapes with the rice-water evacuations, and 

 these are believed to be only infective at a certain stage of their 

 decomposition, and not when fresh. Evidence in support of 

 this view resulted from the experiments made by Thiersch and 

 Sanderson. In experiments on mice by Sanderson, with the 

 liquid one day old, ii per cent, of them died ; two days old, 36 

 per cent, died ; three days old, 100 percent. ; four days old, 71 

 percent.; five days old, 40 per cent.; and at six days old, it 

 became innocuous again. The morbid appearance, found in 

 mice after death, appeared to be consistent with the view that 

 death resulted from Cholera. 



Regarding the more recent views, and the discovery of the 

 Comma Bacillus by Koch, which is usually found in the evacu- 

 ations, I will say nothing. The gentlemen, who present their 

 views this evening, will exhibit and explain the peculiarities 

 and mode of growth distinguishing it from other forms similar 

 in appearance. 



NEUROSIS OF CHOLERA. 



BY L. SCHONEY, M. D. 



{Read October list, 1887.) 



One of the ingenious theories propounded with regard to the 

 cause of Cholera is that of Dr. Chapman. We may call it the 

 Neurotic Theory, Dr. Chapman ascribes Cholera to a dis- 



