l899-'oo TRANSACTIONS 141 



pointed to look after the matter, and an engineer, whose special 

 duty it is to see to the protection of the supply, and its proper 

 distribution. Compare this with the case of 5,000 families resi- 

 dent in the country. It is probable that these obtain their water 

 supply from 5,000 different wells, each having its own peculiarities 

 of situation and protection, and each well having a special inter- 

 est, only to the particular family drawing water from it. If the 

 owner of one of these wells desires to have it examined with a 

 view to determining its purity, the total cost of such examination 

 falls upon himself, and any opinion procured by him, has no 

 value for his neighbors, and does not help them to a conclusion 

 as to the safety or otherwise of their wells ; yet it should be a 

 matter of great importance to each of them to know that, not 

 only his own, but his neighbor's well is pure. If one well be- 

 come polluted with typhoid germs, for example, this disease may 

 spread over the whole neighborhood, as has happened again and 

 again. If a school well, or the well of a resident near a school 

 or church, and likely, on that account to be visited by many 

 people, becomes infected with typhoid, or diphtheria, or cholera, 

 or other germs, it may become a prolific source of the disease. 

 I have often asked myself this question : "Can no way be de- 

 vised whereby useful information, regarding the safety of coun- 

 try wells can be obtained, which will be comparatively inexpen- 

 sive, and therefore practicable ?" No answer is forthcoming that 

 fully satisfies all requirements ; but I believe that the suggestion 

 I am about to make, goes some way towards solving the difficulty 

 and is, at least, worth serious attention. 



In the first place, we may conclude that normal ground- 

 water is a safe source of supply. Owing, however, to the fact, 

 that the soil and sub-soil of one locality differs from that of an- 

 nother locality in nature of constituent materials, their depth, 

 compactness or porosity ; contiguity to neighboring heights, of 

 land, or to swamp ; as well as in amount of annual rainfall, we 

 cannot expect ground-water to have the same characters every- 

 where. What we may expect is that in a given geological and 

 topographical area (perhaps extending over many square miles, 

 perhaps less than one square mile in size), the ground- water will 

 have a certain definite character. If the soil consist largely of 

 limestone debris, we shall find bi-carbonate of lime in the water, 

 if gypsum characterize the soil of the locality, we shall find sul- 

 phate of lime in the water, if chlorides be present in the soil, then 



