120 INFECTION AND IMMUNITY 



methods of getting rid of these dangerous domestic 

 pests. But the most important sanitary precaution 

 consists in the immediate disinfection of all cholera 

 excreta. This should be effected so far as possible 

 in the sick-room or its immediate vicinity. And the 

 dangerous mild cases of choleraic diarrhoea should be 

 looked for and placed under treatment, an important 

 part of which will be complete rest and isolation 

 under conditions which admit of the necessary meas- 

 ures of disinfection. 



A channel of infection not yet mentioned, is 

 through the soiled underclothing or bed linen of 

 cholera patients. Laundresses have not infrequently 

 contracted the disease as a result of handling such 

 infected articles. For this reason disinfection by im- 

 mersion in boiling water or a suitable disinfecting 

 solution should be carried out in the sick-room, or an 

 adjoining apartment. 



The cholera germ, which was discovered by the 

 German bacteriologist, Dr. Robert Koch, in 1884, is 

 usually seen in the form of slightly curved rods, re- 

 sembling somewhat a comma, and was first spoken of 

 as " the comma bacillus of Koch." But these slightly 

 curved rods may grow out into longer or shorter 

 spiral filaments, and the so-called comma bacillus is 

 described in systematic works upon bacteriology as a 

 "spirillum" (Spirillum cholera Asiatics). It is con- 



