Fresh Water Algae in Vicinity of Montreal 401 



pends largely on the chemical qualities of the water. The 

 good results from cultures in Montreal water were 

 marked. It was learned from the City Analyst" 

 that in connection with the filtration plant the Montreal 

 Water-works regularly placed a definite quantity of 

 hypochlorite of lime in the water supply as a disin- 

 fectant. Less than one part of the bleach to a million 

 parts of water were used. While this amount de- 

 stroys the deleterious bacteria, it was proved to have no 

 ill effects upon higher organisms. 



The following analysis obtained from the Chemical 

 Department of McGill University, in addition, shows 

 that the water contained the nutrient salts necessary for 

 normal growth: 



Total solids 11 . 13 parts per 100,000 



Temporary hardness 7.39 



Permanent hardness none 



Organic and volatile matter. 1.92 



Free NH 3 0.0026 



Albuminoid NH 3 0.0154 



Nitrogen as nitrate . 65 



Nitrogen as nitrite none 



Oxygen as used in KN0 4 test 0.45 



Chlorine 0.6 



Silica 0.24 



Lime 2.5 



Magnesia . . . 3.2 



Iron oxide and alumina .... 0.76 



In the Botanical Laboratories, where these experi- 

 ments with algas under artificial conditions were con- 

 ducted, the windows facing the north were used during 

 the early part of the winter for the aquaria. Towards 

 spring, when experiments were made with nutritive solu- 

 tions, parallelcultureswereplacedin both north and south 

 windows, but no difference in effect could be observed. 

 Toward the latter part of March, when the sunlight was 

 much stronger than it had been during the winter, it 



