180 Thk Ottawa Naturalist. [March 



Cities having even a very hard water supply do not show the 

 prevalence of any disease that can be attributed to the water 

 and we may conclude that the lime compounds present do not 

 work any injury to health. As already remarked sudden changes 

 from one character of water to another, whether hard to soft 

 or soft to hard, may cause disturbance in the system, but such 

 will only be temporary. The system requires lime to build up 

 its skeleton and for its other tissues and it may take it from the 

 water as well as from the food; there is nothing to prove that 

 the lime taken in the water is not as readily assimilable as that 

 in the food stuffs we consume. Consensus of opinion points to 

 a moderately hard spring water, in which all possibility of con- 

 tamination is out of the question, as probably the best supply, 

 but such unfortunately is very hard to find. 



2. Is distilled water wholesome? The only argument that 

 can be urged against its use for drinking is that it does not con- 

 tain the necessary mineral elements for the building up of the 

 tissues and for the replacement of the daily outgo of these 

 elements.' The answer is that in the ordinary, normal diet there 

 is such an abundance of the mineral salts that the absence of 

 them in the drinking water need cause no alarm. There is much 

 to be said in favor of distilled water, as it should be free from all 

 forms of organic matter and disease germs. 



3. What means can the householder take towards making 

 a suspicious water harmless? Undoubtedly the best plan is to 

 boil the water for from 5 to 1 5 minutes. This is the most efficient 

 safeguard that can be proposed for the individual. Household 

 filters, though removing suspended matter, are seldom to be 

 depended upon to deprive the water of germ life and at the best 

 require constant attention and cleansing to be kept even fairly 

 efficient. The addition of hypochlorite of lime, now largely 

 used in the purification of city supplies is not readily applicable 

 in the house and cannot be regarded as equal to boiling for the 

 destruction of germs. The boiled water may be rendered pal- 

 atable and the "flat" taste removed, by being allowed to cool 

 in the open air. 



And now in conclusion, I must emphasize two points, The 

 first is the insidious character of polluted water. The danger 

 that lurks in water polluted with excretal products is not alwavs 

 apparent. This fact must not be lost sight of. There may be 

 no outbreak of typhoid fever, but it may be generally under- 

 mining the health. In far too many cases the well goes unsus- 

 pected until the victim is stricken down. The moral is, ascertain 

 the purity of the supply. 



And the second point is that there is abundance almost 

 everywhere of pure water. There is no better watered country 



