88 



HALIFAX WATER WORKS. JOHNSTON. 



Another sample, taken from Chain Lakes near the pipe- 

 house, gave: 



Inorganic matter . . 2 . 48 grains to the gallon. 



Organic " 2.68 " 



Total 5.12 ' " 



The inorganic matter consisted chiefly of alumina and iron, 

 with silica (soluble), common salt and a mere trace of lime. 

 The water belonged to the class of soft waters such as are col- 

 lected in districts where there are no rocks capable of yielding 

 soluble substances. The sources of the impurity taken up by 

 the water in its passage through Chain Lakes was discovered in 

 the form of a very peculiar deposit found in Upper Chain Lake 

 extending over the greater portion of the lake bottom, of a 

 thickness of over five feet in level places. It varied in con- 

 sistency from that of soft cheese to that of baker's bread, and 

 in color from whitish to dark ferruginous brown, in some places 

 nearly black. It consists to a very large extent of the remains 

 of microscopic organisms belonging to the class of infusoria. 

 The chemical analyses of four samples is as follows : 



This deposit has no doubt originally consisted of swamp 

 muck formed by the remains of plants, infusoria, etc.,, but 

 by the long subjection to the action of water passing over it has 

 lost much of its organic matter. 



A few specimens of fresh-water sponge (Spongilla), whose 

 decay gives a very offensive odor to water, were found in Upper 

 Chain Lakes in 1878, a'nd in 1883 the growth was increasing 



