BY J. BBOWNLIE HENDERSON, F.I.C., F.C.S. 135 



re-absorb air, tank water gives the safest and most palatable 

 water that it is possible to have. 



Now with regard to the possibility of harmful results aris- 

 ing out of the continued use of tank water containing zinc in 

 solution I of course cannot speak with authority, but I will 

 give the chief references that I have been able to find after a 

 rather extended search, though unfortunately owing to the 

 absence of any good library in Brisbane I have not been able to 

 make the search as complete as I would have liked it to be. As 

 it would be exceedingly inconvenient for any one in Brisbane to 

 get the following books or journals for reference, I give the 

 contents of each reference as fully as possible. 



Text Books. 



Most text books vaguely condemn the presence of zinc in 

 ■drinking water. The following two may be taken as fair 

 examples : — 



Mason's " Examination of Water,'' 1899 edition, j). 80. — 

 " Zinc is not a cumulative poison, but its presence in water 

 is nevertheless distinctly objectionable." 



Davis's ^^ Potable Water," 1891 eiL, p. 21. — "Galvanised 

 iron pipes are also liable to render dangerous the water that passes 

 through them ; such waters contain zinc, but the amount is 

 generally very small." 



The following references are much more informative : — 



Professor Dixon Manns " Forensic Medicine and Toxicology," 

 1898 ed., p. 469, states :— 



" Chronic poisoning by zinc has been observed, chiefly in 

 smelters of the metal. The symptoms to some extent resemble 

 those produced by lead ; derangement of the digestive organs, 

 colic with constipation or more frequently diarrhoea ; indications 

 of peripheral neuritis have been observed. Gastric symptoms 

 have resulted from drinking water or milk stored in zinc lined 

 vessels." 



Dr. Thresh's " Water Supphj," 1896 ed., p.p. 10, 209, 

 210, 211, and 418:— 



" Waters which act on lead appear also to have the power 

 of acting upon zinc, and of forming poisonous compounds 

 which dissolve freely in the water. As the physical characters 

 of the water are not altered, the presence of the metal may 

 remain unsuspected, unless some obscure form of illness leads 

 the medical attendant to have it examined. When water which 

 •contains an appreciable amount of zinc is heated in an open 



