HALIFAX WATER WOKKS. — JOHNSTON. 91 



There are two points in the above that require special con- 

 sideration, viz., the high figures for albuminoid ammonia and 

 tlie oxygen absorbed. An opinion l)ased on those leads to but 

 one result, that the water is impure. 



Accordi'ng to AVanklyn, Chapman, and Smith, the limit for 

 albuminoid amnionia is 0.066 parts per million for a good 

 water, Avhile here we have from 0.1470 U) 0.1S14, which is a 

 very large excess. 



This impurity is chieliy attributable to contamination with 

 animal matter, but situated as the lakes are and considering 

 their surroundings its origin is not apparent. Xevertheless, 

 there is no question but that Lower Chain Lake must in the 

 spring receive a large amount of impiu'itv from the accumu- 

 lations of the winter wakshed into it from the road along its 

 banks. Ragged Lake under this head is the least of all. though 

 its figures are much higher than they should be. As to the 

 oxygen absorbed, 3 parts per million is considered to be the 

 limit of a water of medium purity, while we have here more 

 than 6. 



This does not necessarily condemn the water, peaty water 

 not being considered injurious. Still the figures are high, and 

 the water carries a large amount of organic matter and shr)uld 

 be filtered before use in all cases. 



The folloAving is extracted from a re]>ort of Prof. George 

 Lawso'n on the foregoing analysis : — 



"The rasult of analysis showing Ragged Lake water to 

 contain 0.1470 parts per million of albuminoid nitrogen and 

 the other samples from 0.1671 to 0.1814, the average of the 

 whole being 0.1714, affords sufficient evidence of organic im- 

 purity in all the waters. The high rate of oxygen absorbed 

 tells the same tale. I'n such cases it is usual to regard fhe 

 albuminoid nitrogen as having its origin in sewage or animal 

 matter, iience the great stress laid by water analysts upon the 

 albuminoid nitrogen. Witho^it further knowledae of them. 



