72 
Journal of Agricultural Research 
Vol. XXVI, No. a 
several times with ether, and the colorless ethereal liquids, after being 
washed with a little water, were added to the ether extract from the main 
portion of the original liquid. On finally concentrating the aqueous liquid 
there was obtained a quantity (25 gm.) of nearly colorless crystals, 
which were further purified by treatment with a little animal charcoal 
and recrystallization. The crystals, after being dried in a desiccator, 
yielded a solution which did not reduce Fehling’s solution until heated 
with an acid, and they possessed all the other characters of sucrose. A 
determination of the specific optical rotation gave the following result: 
0.6312 gm. dissolved in water to the measure of 25 cc. at 20° C. gave 
4-3.33 0 in a 2 dcm. tube, whence [ckJd^ +65.9°. 
These figures are in close agreement with those required for sucrose, 
which has [a] D + 66.5°. 
The main portion of the alcoholic extract, from which the above- 
described crystals of sucrose had separated and from which the alcohol 
had been removed, gave no precipitate on further dilution with water, 
and consequently no resinous material was present. On the subsequent 
addition of a solution of basic lead acetate an abundant brick-red precipi¬ 
tate was produced. This was separated by filtration and well washed 
with hot water. 
BASIC I,E£AD ACETATE PRECIPITATE 
The material precipitated by basic lead acetate, including the small 
amount previously obtained by the purification of the sugar solution, was 
mixed with water and decomposed by hydrogen sulphid. The filtrate 
from the lead sulphid was concentrated, when it formed a reddish-yellow 
liquid. It was extracted several times with ether, but this removed only 
a small amount of amorphous material, which, when dissolved in water, 
gave a grayish-brown coloration with ferric chlorid, thus indicating the 
possible presence of a little tannin. After extraction with ether, the 
liquid abundantly reduced Fehling’s solution, and evidently contained 
considerable sugar which had been occluded in the original lead precipi¬ 
tate. 
FII/fRATE PROM THE BASIC BEAD ACETATE PRECIPITATE 
This liquid was first treated with hydrogen sulphid for the removal 
of the excess of lead, the mixture filtered, and a current of air passed 
through the filtrate to expel the dissolved gas. The liquid then pos¬ 
sessed only a faintly yellow color. It was extracted several times with 
ether, but only a very small amount of amorphous material was thus 
removed. After concentrating the liquid it formed a viscid, reddish- 
yellow sirup which gave no reaction with the ordinary alkaloidal reagents 
or with a solution of mercuric nitrate. It readily reduced Fehling’s solu¬ 
tion and on heating with a caustic alkali developed ammonia. A small 
portion of the sirup yielded an abundance of d-phenylglucosazone, which 
on crystallization from 60 per cent alcohol separated in fine yellow needles, 
melting and decomposing at 217-218° C. It therefore consisted chiefly 
of a reducing sugar. 
EXTRACTION OF THE CHUFA WITH WATER 
SEPARATION OF STARCH AND EVIDENCE OF THE PRESENCE OF AN ENZYM 
One hundred gm. of the ground tubers were mixed with 1000 cc. of 
water and allowed to stand over night. The mixture was then strained 
through a fine cloth, and the deposited starch collected and washed, 
