Report on the Bacteriology of Water. 



135 



f. Bakteriologie,' vol. 13 (1893), p. 313) that the addition of sodium 

 chloride, and of other salts in certain proportions, to water containing 

 the cholera bacilli causes a most remarkable multiplication of the 

 latter, as may be seen from the following table, given by Trenkmann, 

 which exhibits the effect of making such additions to a sterilised well 

 water, which had been purposely infected with, cholera bacilli. 



Addition of various Salts to Sterilised Well Water containing 

 Cholera Bacilli. 



* 2527 drops = 1 c.c. 



These results show that the presence of an unusually high propor- 

 tion of salts may not improbably have played an important part in 

 the distribution of cholera by means of the water of the Elbe in the 

 recent Hamburg epidemic, and possibly also by means of the 

 Thames water in some of the former London epidemics, as at that 

 time the metropolitan supply was in part derived from the tidal 

 portion of the river. 



In view of these circumstances, it appeared to me to be of con- 

 siderable interest to ascertain whether and in what way the behaviour 

 of the typhoid bacillus in water is affected by additions of salt, and, 

 with this object, the following experiments were undertaken : 



