Drinking- Water and some of its Impurities. 125 



obtain pure water from city wells. Before digging a well, 

 even in the country, the nature of the soil should be con- 

 sidered, and care taken to have it sufficiently distant from 

 any vault or barnyard to avoid all possible contamination 

 of the water. 



Union College, 



Schenectady^ June 25, 1877. 



The subject of the foregoing paper was discussed by 

 Prof» Prescott, and Dr. Stevens, the latter remarking as 

 follows : ' 



The important fact in the subject of this paper is one 

 which has not until recently received the attention which 

 its just importance demands, namely, that dangerous con- 

 tamination of drinking water^depends, not upon the quantity 

 of organic matters which it may contain, but upon the pre- 

 sence of the specific poison which generates typhoid fever 

 and kindred diseases. 



This poison emanates from the excretions of the sick 

 from these diseases, and such excreta when mingled with 

 drinking-water, even in most minute quantities, . are ex- 

 ceedingly dangerous. 



One may drink water with safety for a long time which 

 contains very large quantities of organic matter. The fact 

 related by Mr. Prescott of drinking the water expressed 

 from the moss of a swamp for many days together, without 

 harm, illustrates^_^this fact; but had even the smallest 

 quantity of the excretions from a typhoid patient found its 

 way into this water, our friend would not, in all probability, 

 have been with us to-night to relate his adventures in the 

 mountains. 



A striking illustration of the dangerous quali ties of 

 water which may run perfectly pure and comparatively 

 free from organic matter is found in the case of the Swiss 

 village mentioned in the paper just read. Here water 



