452 SPIRILLUM CHOLEILE ASIATICS. 



of which the individual patients who receive the 

 infective material from one another, reproduce it, and 

 pass it on, represent the links. The whole distance 

 from India to Europe could not in former times be 

 traversed by one and the same cholera patient ; a chain 

 of patients was always necessary, this chain stretching 

 without interruption along the overland route; or the 

 disease was carried by ships sailing from India to 

 Europe, the chain being in that case shorter, correspond- 

 ing to the shorter time required for the journey. These 

 two chains were evidently not easily established ; even 

 the shorter one which suffices for the sea journey was 

 difficult to obtain, because on ships the opportunities for 

 the propagation of the disease are relatively unfavourable. 

 It is, moreover, evident that any interruption of the 

 chain, any failure in the transmission of the contagium 

 to a new individual, must lead to failure of the spread of 

 Present mode the disease. At the present time the spread of cholera 

 cholera. is rendered very much easier, seeing that the network of 



railways in Low r er Bengal communicates with the various 

 ports of India, so that one and the same patient can be 

 transported to any of the cities on the coast ; and further, 

 because a very small number of patients is sufficient to 

 carry on the disease during the journey from Bombay to 

 Egypt, and the active contagium may be carried from 

 Egypt to the nearest European ports by one and the 

 same patient. In Europe also cholera can be distributed 

 by travellers, and we must remember that even a slight 

 attack of cholera which scarcely causes any noticeable 

 disturbance of the general health, but in which never- 

 theless there is multiplication of the comma bacilli and 

 their deposit in the dejecta, is quite sufficient to transmit 

 the disease. Striking examples, showing to what 

 distances the cholera contagium may be carried at the 

 present time by means of the railway, are furnished by 

 the case observed by Von Pettenkofer, where a child 

 suffering from cholera carried the disease direct from 

 Odessa to Altenburg, and the case published by Biermer, 

 where the cholera contagium was brought directly from 

 Rome to Zurich. 



