HALIFAX WATER WORKS. JOHNSTON. 91 



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

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

 the oxygen absorbed. An opinion based on those leads to but 

 one result, that the water is impure. 



According to AYanklyn, Chapman, and Smith, the limit for 

 albuminoid ammonia is 0.066 parts per million for a good 

 Avater, while here we have from 0.1470 to 0.1814, which is a 

 very large excess. 



This impurity is chiefly attributable to contamination with 

 animal matter, but situated as the lakes are and considering 

 their surroundings its origin is not apparent. Nevertheless, 

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

 spring receive a large amount of impurity from the accumu- 

 lations of the winter washed 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 should 

 be filtered before use in all cases. 



The following is extracted from a report of Prof. George 

 Lawso'n on the foregoing analysis : 



"The result 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 the 

 albuminoid nitrogen as having its origin in sewage or animal 

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

 albuminoid nitrogen. Without further knowledge of them. 



