270 TEXT-BOOK OF BACTERIOLOGY. 



of causing changes identical with those observed in human cholera. 

 Further information could not be expected from the experiment. 

 At most, all that could be accomplished in this direction was the 

 transmission to man, the only organism susceptible under natural 

 conditions. 



The correctness of this supposition has, in fact, been accidentally- 

 established. During the so-called "Courses on Cholera" at the 

 Imperial Board of Health (delivered for the purpose of making the 

 existence of comma bacilli more widely known), one of the attend- 

 ants, having in some way neglected the necessary precaution, was 

 infected by the bacteria and fell sick from a violent attack of chol- 

 erine. He had very frequent watery and colorless discharges, 

 great weakness, unquenchable thirst; almost complete suppression 

 of urine; there were shooting pains in the soles of the feet, etc., and 

 quantities of genuine comma bacilli were found in the faeces. 



Thus at last the results of microscopic investigation, cultivation, 

 and transmission are in satisfactory' accord, and we can no longer 

 doubt that the comma bacilli are the true and sole cause of the 

 cholera asiatica of man. 



We now turn again to the question. How does the bacterium 

 get into the body, how does it there produce disease, and how can 

 the peculiarities of this disease be explained by the living proper- 

 ties of the micro-organism ? 



We are here touching upon a matter engaging the attention of 

 the scientific world and leading to the most adverse opinions. 



Discussions concerning the nature and mode of origin of cholera 

 have never been wanting since the time when it first made its ap- 

 pearance in Europe. As long as a quarter of a century ago, Pet- 

 tenkofer (an eminent authority on hygiene and epidemics) had ex- 

 pressed a characteristic opinion regarding the development of 

 cholera formed on the basis of very detailed and extensive epi- 

 demiological observations. This view soon found general recog- 

 nition. 



Pettenkofer's theory is essentially as follows: Cholera is not 

 transmissible from man to man. The poison originates in the soil 

 under certain conditions. The presumable cholera germ develops 

 by virtue of particular properties of the soil, which may be charac- 

 terized as local and temporal disposition, and from these properties 

 arise the causa morbi. These special properties of the soil, its local 

 and temporal disposition, are mainly founded on changing condi- 

 tions of moisture and heat, on a phj'sical state, and, finally, on " im- 

 pregnation " — i.e., on its possession of nourishing substances for the 

 lower organisms. 



