§ 133. BEETS, TUENIPS. 259 



and determine glucose in an aliquot part of the solution, 

 having first added water, if necessary, to make the volume 

 of the solution one that can be easily divided into aliquot 

 parts ; calculate the result obtained for saccharose, if the 

 root examined was the sugar beet ; in other roots, and in 

 the sap of plants, glucose is found, as well as cane sugar, 

 and the determination should be made accordingly (§ 83). 



To examine the root in its fresh state for sugar, enclose 

 a weighed quantity of the finely grated root in a flannel 

 bag, and press the sap out of it ; weigh the press-cake, 

 and determine water in one portion of 20-30 grms. by 

 desiccation at 100° ; on the basis of this determination, 

 the amount of sugar still remaining in the cake can be 

 estimated, the solution in the cake being of course of the 

 same strength as that expressed. 



Weigh or measure the sap that was pressed out, and 

 determine sugar in an aliquot part of it. 



In the case of the sugar beet, it may be assumed with 

 tolerable safety that it contains 94" \^ of water, and we 

 may therefore express a small quantity of the sap from a 

 weighed quantity of the grated root, and determine sugar 

 in 50 c.c. of it, in the usual manner (§ 83). 



An approximate estimation of sugar in beets may be 

 made by determining their specific gravity according to 

 the method described in § 35, 6. 



Take 10-12 beets from different parts of the lot, clean 

 them carefully, cut each one in four equal sections, across 

 its longitudinal axis, and use the second piece from the 

 top for the determination of the specific gravity. The 

 temperature of the saline solution should be about 18° C 



The relation between the specific gravity of the beet 

 and the percentage of sugar, as well as of total dry sub- 

 stance, is given in Table VI. 



When, in these estimations of sugar with the cupric so- 

 lution, the solution of sugar is not properly clarified by 

 the plumbic acetate, heat a measured quantity of it nearly 



