CHOLERA. 183 



themselves complete, observations of the great epidemio- 

 logists of this and other countries are valueless ; and as in 

 time a more perfect knowledge of the conditions favourable 

 or unfavourable to the growth of the organism is obtained, 

 it may be expected that all observations made Vith care by 

 those whose only desire is to get at the truth, will fit in and 

 take their place in a large and comprehensive scheme 

 through which there will ultimately be a possibility not only 

 of understanding the disease more thoroughly, but of re- 

 moving or combating its causes. 



It has already been pointed out how Pettenkofer's obser- 

 vations may be made to agree with Koch's ; it has been seen 

 that the apparently contradictory statements on the subject 

 of the spread of cholera along the lines of pilgrimage and trade 

 have been more or less satisfactorily explained and reconciled 

 on the assumption th^t the bacillus is the cause of the disease. 

 Then, too, the well-known facts of the association between 

 cholera and gastric and intestinal disturbances of various 

 kinds ; between it and consumption of various articles of food 

 and of water from sources which are probably contaminated, 

 or in which the presence of the cholera organism has been de- 

 monstrated, and the facts connected with climatic conditions, 

 ground water and subsoil drainage, temperature and special 

 local conditions, may all be satisfactorily explained on Koch's 

 comma bacillus theory. These explanations, taken with the 

 fact that the comma bacillus is invariably found during cer- 

 tain stages of the disease, that it has never yet been found in 

 any but typical cases of cholera, that with it the disease has 

 been produced in animals, experimentally, and one might 

 also say in man, though accidentally (at the cholera course 

 in the Hygienic Institute in Berlin), make it impossible for 

 us to shut our eyes to the fact that in the cholera bacillus we 

 have the only suggested causal agent that will allow of a 

 satisfactory explanation of the mass of observations made up 

 to the present. It had already been demonstrated that the 

 bacillus was found only in the intestinal canal, when it 

 naturally suggested itself to Koch that the symptoms of 

 cholera were to be explained by the theory that in this 

 disease there was absorption from the intestine of some 

 soluble poison produced by the bacillus in situ ; that there 

 was, in fact, a local formation of the poison, but a general 

 absorption into the system (the " Intoxication " theory). This 



