COMPOSITION, AND PROPERTIES OE KOJI. 
27 
III. Maltose. The optical rotations observed were, as 
follows : 
Maltose alone.13.0° 
Mixture, after heating. 9.2° 
Assuming that no alteration of the maltose had taken place 
during its digestion with yeast extract, the rotatory power of the 
mixture would have been 9.0°. As the result of the actual 
observation was very nearly the same, we may conclude that 
maltose is not affected by yeast extract. Another experi¬ 
ment made with invertin precipitated from the aquous extract 
of triturated yeast with strong alcohol and redissolved in 
water gave the same result, viz., : 
Rotation of the maltose solution alone.33.5°. 
„ of the yeast ferment, after heating... 4.0°. 
,, of the mixture, after heating.25.0°. 
As the mixture consisted of 50 c.c. of maltose solution and 
20 c.c. of dissolved yeast ferment, its rotation must have ori¬ 
ginally been 25.1°. After heating 25.0° were observed, 
whence the yeast ferment had not influenced the maltose. 
1V. Inulin was also not affected by solutions of the yeast 
ferment. The rotations observed were the following : 
50 c.c. of inulin solution, fresh.—2.8°. 
25 c.c. of yeast extract, heated.+1.0°. 
mixture, after heating.— 1.5°. 
Calculated from the rotations of the solutions applied, the 
mixture should have shown—1.5°, which happens just to 
coincide with the rotation observed. 
T. Starch. Several experiments were made with starch, 
previously extracted repeatedly with strong alcohol to remove 
