BY R. GREIG SMITH. 



221 



The influence of lemdose. — Having found that levulose was a 

 suitable sugar, an experiment was made to determine the most 

 favourable quantity. The figures given are the percentages 

 obtained at the end of the third day. Asparagine was the nitro- 

 genous nutrient in the medium. 



The Slime from varying Quantities of Levulose. 



Percentasre of levulose. 



Grams of slime from 100 c.c. of medium.* 



None. 

 1 

 2 



4 



6 



8 



10 





 14 

 17 

 15 

 13 

 10 



Fig. 1. — The Influence of Levulose. 



It is evident that the optimum percentage of levulose lies 

 betw^een 2 and 4 per cent. Upon plotting the numbers it is 

 found that the yield reaches a maximum with about 2J % of 

 levulose. The depressing effect of larger quantities is clearly 

 shown. 



The influence of salts. — The saline constituents of the medium 

 are undoubtedly of considerable importance, and it has been 



* Asparagine 0-3, potassium citrate 0-6, tannin 0-3, agar 2, water 100 grms. 



