RELATIVE PROPORTIONS OF THE SUGARS. 191 
II., we find that the specific gravity 1-083 corresponds to 
11° Beaumeé’s hydrometer, or to 20 per cent. of cane sugar.* 
The saccharometer is a hydrometer upon which the per 
cent. of sugar may be read off directly, without reference 
to a table, and this form should be in general use. 
The following tests may be applied when it is desired to 
determine approximately the relative proportions of cane 
and uncrystallizable sugars, and impurities in a given sam- 
ple of cane juice. To a given weight of the fresh juice, 
filtered through a cloth to remove fragments of pith, etc., 
and poured into a narrow jar or glass test cup, add care- 
fully a few drops of a strong solution of subacetate of lead, 
stir it with a glass rod, and let it remain at rest until the 
upper portion of the liquid becomes clear. Decant a little 
of this into a small phial or test tube, and add a single drop 
of the solution of subacetate of lead. If the liquid becomes 
clouded as before, return to the test jar what was taken out, 
and add a little more of the lead solution. Let the precip- 
itate settle, and test again, continuing to add the subacetate 
in small portions at a time, until it ceases to disturb the trans- 
parency of the sugar solution.t Take a wide tube of about 
* Since the refractive power of a body in solution is not influenced by 
chemical combination, it is possible that a more valuable instrument 
than the hydrometer might be constructed, which would indicate the per 
cent. of sugar in solution. 
t Subacetate of lead possesses the valuable property of separating 
from the saccharine solution in the insoluble form, any other organic sub- 
stances which it contains. In order to determine the quantity of impu- 
rities, therefore, throw the whole of the precipitate obtained as above, 
upon a filtering paper, wash it with pure water upon the filter, allowing 
the water to fall upon it in a fine stream. Repeat this again after the 
water has passed off, let the precipitate remain upon the filtering paper 
until it is nearly dry, remove it carefully from the paper with a thin-bladed 
knife, place it in a thin capsule of silver or copper the exact weight of 
which is known, and then dry it perfectly in a water or steam bath. 
Weigh the capsule and its contents, and subject it to a heat strong 
