1907. 1 



MASON— ACTION OF WATER UPON METALS. 115 



In a private letter of more recent date the president of the 

 above mentioned board says : " If there had been any harmful ef- 

 fects of the presence of zinc in the public drinking waters of the 

 state that fact would have undoubtedly been brought to our atten- 

 tion. No statement to this effect has been made, nor has there 

 seemed to this board reason suspecting serious danger from this 

 source." 



As an instance of long continued use of a water containing 

 much zinc, the case of Brisbane, Queensland, should be quoted. 

 In that city rainwater tanks built of galvanized iron are found in 

 all the houses. The water, which is in common use, contains about 

 17. 1 parts per million of zinc, yet no harmful effects have been 

 observed.^ 



In his experience the writer has been unable to trace any evil 

 effect due to the presence of zinc in drinking water, even when 

 the quantity rose as high as 23 parts per million in a water which 

 is in constant use. It might be well to add, that in the particular 

 case just cited the zinc was derived from a long stretch of galvan- 

 ized iron pipes and the amount of the metal present was subject 

 to great and frequent fluctuations for reasons that were not ap- 

 parent. 



It must be admitted however, that, even on the assumption that 

 the presence of zinc in a water is of no sanitary significance, its being 

 there is nevertheless not desirable, and the probability of a supply 

 being able to dissolve it should be determined and reported. 



What can now be said with reference to some convenient and 

 standard method of reporting the possible action of water upon 

 any of the common metals ? 



The suggestion offered is this: — Let the action, whether solu- 

 tion or erosion, be stated in parts per million, and let it be that of 

 one litre of water acting upon one square decimeter of bright metal 

 for one hour at 15° Centigrade. 



The mode of procedure followed by the writer is to submerge 

 a piece of bright sheet metal, one decimeter square in two liters 

 of water contained in a wide-mouthed bottle. The water is oc- 



^ Hazen, Eng. Nezus, April 4, 1907. 



