On the Diastase of Koji. 323 



in the middle of the day, and thus the more rapid action is explained. 

 In the same way, the average temperature during the series first 

 mentioned may have been more nearly 15° C. than during the last 

 series, although I do not know this to have been so. It is, at any 

 rate, a possible cause of difference. 



No certain conclusions can, I think, be drawn as to the reaction 

 being expressed by any definite chemical equation ; there is at first in 

 all cases a very rapid fall ; and, in Curve C the specific rotatory 

 power, after twenty minutes, nearly agrees with that required by Brown 

 and Heron's equation ISTo. 7, before alluded to ; but, after this, the 

 absorption of water by the maltose would make the curve very regular, 

 and it would show no breaks in its continuity. 



The two following series of experiments were conducted at a tem- 

 perature of 40° C, the flask containing the mixture being immersed in 

 a water-bath kept at that temperature, and samples were taken at 

 certain intervals of time. The solution used for determining the total 

 solid matter from its specific gravity was rapidly cooled by means of 

 ice, and the other portion in which the specific rotatory power was to 

 be determined was poured into a dry flask containing a little salicylic 

 acid, as recommended by Brown and Heron, and also rapidly cooled . 

 Deduction was made for the amount of koji solution added, as in the 

 previous experiments. The two series of experiments differ only in 

 the relative proportions of koji and starch used — that in the first 

 series being 5 grms. of koji to 10 grms. of starch ; and, in the second, 

 10 grms. of koji to the same weight of starch. 



Table XIV.— Action of Koji Extract upon Starch at 40° C. 

 10 grms. of starch to 5 grms. of koji. 



Time. 



Dry starch 

 in 500 

 cub. centiras. 



Weight of 

 Jcoji used, 

 as extract. 



Total starch 

 products . 



Specific 

 rotatory 

 power. 





Grrras. 



Grms. 



Grrms. 









10 



5 



10-08 



167 









10 -08 



127 



+ 92 hours at 15° C. . 





55 



10 25 



106 



