NOTE AS TO THE MEASUREMENT OF THE ACTION 

 OF WATER UPON METALS. 



By WILLIAM PITT MASON, M.D. 

 {Read April ig, iQoy.) 



Reports recording that a water contains so many parts per 

 million of lead, zinc or other metal are common enough, but it is 

 rare to find advance statements of what a water is capable of doing 

 in the way of dissolving metals should opportunity be afforded it 

 of coming in contact with them. In other words, a client who 

 possesses a water supply which is very desirable at its source is 

 seldom informed of the possible damage which may result thereto 

 by reason of its being conveyed through metallic piping. 



After the pipes have been laid and the water admitted to them, 

 record is made of the result as to the metallic solvency, but little 

 is found in the nature of a prophecy antedating the outlay of capi- 

 tal ; which prophecy had it been uttered in time, might have had ma- 

 terial bearing upon the investment. Again, if, as occurs in a few 

 instances, the client be told that the water under examination is 

 capable of acting upon certain metals, he is not given the informa- 

 tion in such quantitative form as will enable him to make com- 

 parisons between it and other waters with reference to this 

 property. 



It is well known that all waters do not equally possess the 

 power to attack metals and it is proper to ask that, granting such 

 power to exist, how far is its exercise objectionable from a sanitary 

 point of view ; or, to state it differently, what amount of metallic 

 salts in solution may be allowed with safety? 



The interesting case is given of " A water from the tail-race 

 of a gold and silver mill which showed the presence of 350 parts 

 of lead, 51 parts of copper and 1666 parts of arsenic oxide per 

 million of water. This water, which was supposed to have caused 

 the death of a number of cattle, was so highly charged with arsenic 



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