427 
The temperature of liquids influences their gravity. They 
expand by heat and contract by cold, and consequently their 
specific gravity are increased hy the latter and diminished by 
the former. ; 
Thus a grape must whose weight is taken at a temperature over 
15 degrees C. or 60 degrees F. appears lighter than it really is; 
therefore the reading should be forced. 
Spirit, on the other hand, at a temperature higher than normal 
appears lighter in weight; that is to say, higher in strength, and a 
deduction is made to correct the error. 
As grape must contains other substances beside sugar, the real 
sugar contents will be from .5 to 2.5 per cent. less than the indi- 
eated per cent. or degree on the saccharometer. As seen above the 
specific gravity of the juice also varies with the temperature; for 
this reason bring the temperature of the juice to the standard 60 
degrees F., or make the corrections of .1 per cent. for every 
3 degrees F. above or below standard by adding if the temperature 
is higher or by substracting if it is lower. 
2nd. The Baumé Scale, which is determined by marking as 
0 degree the point on the spindle of the hydrometer to which it 
sinks when floating in pure water, and as 15 degrees the point to 
which it sinks in a solution of 15 parts by weight of salt in 85 parts 
of water. The interval between these points is divided into 
15 equal parts, and the scale is continued to any number of 
degrees beyond. 
This scale is also very much is use in many branches of indus- 
try. It does not give the density by direct reading, but the density 
can be ascertained either by reference to tables, or by means of the 
following formula, in which mn represents the degrees Baumé 
aS toad on the scale, and D the specific gravity required: 
=144., Thus, 10 degrees Baumé equalsi#4-7,50r 1,075 specific 
eravity. The graduation of the Baumé hydrometer is somewhat 
arbitrary, and its use has only been maintained in practice by wine- 
makers owing to the fact that, by a curious coincidence, degrees 
Baumé, in an unfermented must, also approximately indicate—as 
may be ascertained by referring to the subjoined table—the per- 
centage of absolute alcohol by weight it will have after being sub- 
jected to a complete fermentation. Thus, page 430, a must measur- 
ing 11 degrees Baumé, will give a wine which will contain very 
nearly 11 degrees of absolute alcohol. 
When these instruments are constructed for testing the strength 
of saccharine liquids, the 0 degree is, for reasons previously given, 
placed at the top of the scale. 
