BULLETIN OF THE BUSSEY INSTITUTION. 457 
of this matter, based on the actual weight of the solution exam- 
ined, was found to be (a) D = 63°.22; and on testing the solu- 
tion with Fehling’s liquor it appeared that the reducing power 
was 0.2163, that of pure dextrose being regarded as equal 
to 1,—that is to say, the reducing power was about one fifth 
that of pure dextrose anhydride. It is noteworthy that on cal- 
culating the rotatory power from the quantity of ‘‘ dextrose ’? — 
that is, reducing matter — shown by Fehling’s liquor to be present 
in a measured volume of the solution, the extraordinary figures 
quasi(a) D = 330°.9 were obtained. 
For the sake of testing more explicitly, than had been done in 
any of the foregoing experiments, some current statements as to 
the large percentage of dextrose that may be obtained on hydro- 
lyzing cotton, after treatment with strong sulphuric acid, the fol- 
lowing trials were made : — | 
I. After Flechsig,* 250 grm. of air-dried, well-worn cotton 
cloth, that had been cut into small fragments, were put, little by 
little, into a cooled mixture of 1250 grm. commercial sulphuric 
acid of 92.5% H.,SO, and 420 grm. of water. After the lapse 
of one hour the mixture of cotton and acid was diluted with two 
thirds its volume of water, and the whole was left to stand for 
one day. According to Flechsig, the mixture should now have 
been filtered ; but it was so thick and adhesive that filtration was 
simply impossible. Instead, therefore, of filtering and making 
up the volume of the filtrate to 2.5 litres, enough water (some 
700 ¢.c.) was added to the mixture of acid and cotton to bring 
its volume up to 2.5 litres, and it was found to be practicable to 
filter this mixture slowly with the aid of a suction pump. From 
the filtrate thus obtained, 50 c.c. were taken and mixed with 
water enough to bring the volume up to 900 ¢.c.; and the solu- 
tion thus diluted was boiled over a free flame for six hours, in a 
flasi with reflux condenser, and then neutralized with a hot solu- 
tion of barium hydroxide. Finally, a small quantity of barium 
carbonate was added to complete the neutralization. After filtra- 
tion the neutralized liquor was evaporated to the volume of 97 ¢.c. 
It gave quasi(a) D = 54°.64, and Fehling’s liquor indicated dex- 
trose enough to amount to 30.26% of the cotton taken (regarded 
as dried at 100°). 
* Zeitschrift fiir physiologische Chemie. 7, 528. 
