208 COMPARISON OF SOUTHERN CANE AND SORGHUM. 
On account of the softer texture of the outer covering 
of the stalk of sorghum, and especially on account of the 
greater length of the internodes—or spaces between the 
joints of this cane, as compared with the tropical cane— 
its juice may be more readily and perfectly expressed. 
(See Ch. XIX.) 
11. CuEemicaL ComposiTION—THE JUICE. SS. cane.— 
Properties of the juice: color, pale yellowish gray, faint 
balsamic odor, frothy as it flows from the mill, turbid and 
opalescent, on account of the suspension of finely divided 
matter separable by filtration. A few drops of sulphate of 
copper solution and an excess of caustic potash occasion, 
on heating, a very abundant red precipitate of suboxide of 
copper in the juice, indicating the presence of glucose or 
grape sugar (Fownes). Specific gravity 1:070 to 1-090, 
(Fownes, Evans), but sometimes varies from 1-046 to 1:110, 
or from 7° to 15° Beaumé (Evans). Otaheitan cane juice 
1/070 at 77° F. (McCulloh). The. juice gives a slightly 
acid reaction with litmus paper. 
Sorghum.—Color of the fresh juice, bright green, with a 
tinge of yellow (Chinese cane), or yellowish green, inclining 
to brown in some samples (imphee)—a faint and peculiar 
odor most marked in imphee juice. The presence of grape 
sugar is generally indicated by the application of the copper 
test. Blue litmus paper is instantly reddened when dipped 
into the juice, showing that the solution is acidulous— 
least so in pure Chinese cane juice, most so in red imphee 
(Shlagoova). Specific gravity varies from 1:050 to 1-090, 
or from 7° to 12° Beaumé. Average of crude juice, Chi- 
nese, ripe, 1:075 to 1:080, or 10° to 11° Beaume. 
