SKETCH OF ROBERT K0C11. 263 



organisms were found. It had been further found that this was 

 the only form of micro-organism that was constantly present in 

 the disease ; that it was present in greatest numbers in acute and 

 uncomplicated cases, and in the parts most affected ; while it was 

 never present in other diseases, in healthy persons, and had not been 

 found outside of the body where no cholera was in the neighbor- 

 hood. Then, having disposed of two hypothetical presumptions of 

 contrary tenor, Dr. Koch declared that no other conclusion could 

 be arrived at than that these bacilli are the cause of cholera. 



Although no effects had then been obtained from experiments 

 with comma bacillus upon animals, and direct experiments upon 

 man could not be performed, various observations confirming the 

 theory had been obtained which were almost as good as experi- 

 ments on man. In the water of a tank whence the inhabitants of 

 a village near Calcutta derived their supplies for drinking, chol- 

 era bacilli were found in considerable numbers when the cholera 

 epidemic was at its height. At a later period, when there were 

 only a few cases of illness, the comma bacilli were few in number, 

 and found only at one part of the tank. This was the only in- 

 stance in which these bacilli were found outside of the body. 

 Finally, Dr. Koch maintained that the natural history of the dis- 

 ease corresponds with the various characteristics of the organism 

 in question The bacilli grow rapidly, soon reach their highest 

 point of development, then die, in correspondence with what oc- 

 curs in the intestinal canal. Under ordinary circumstances the 

 bacilli are destroyed in the healthy stomach, while persons suffer- 

 ing already from some disorder of the stomach are most liable to 

 be attacked with cholera. Lastly, the disease dies out in places 

 where the conditions for its continuance are unfavorable ; as 

 bacilli that have no spores will speedily disappear. In experi- 

 ments subsequent to this report, Dr. Koch succeeded in producing 

 cholera by inoculation in some of the smaller animals. 



Dr. Koch's conclusions were contested and some of his evi- 

 dences were disputed by a French commission appointed to in- 

 quire into the causes of cholera ; by certain English pathologists, 

 including Dr. Klein and Dr. Lewis, of Netley ; and were not fully 

 supported by an English commission in India ; but, while they may 

 not yet have been fully accepted, they have not been overthrown, 

 nor do they seem to have lost ground. A bill was unanimously 

 passed by the German Parliament, in 1884, awarding a sum of 

 135,000 marks to Dr. Koch and his companions in this research. 



The principal published works of Dr. Koch are " Etiology of 

 Splenic Fever," 187G ; " Researches on Diseases of Wound-Infec- 

 tions," 1878 ; " Inoculation for Splenic Fever," 1882 ; " Contribu- 

 tions to the Etiology of Tuberculosis," 1882 ; and contributions to 

 the transactions of the German Imperial Health Bureau. 



