On Specifie Gravity. 127 
sliding rod. By employing a body—a glass bulb, for in- 
stance—appended from a balance, as in the usual process, 
we may use water, measured by the Chyometer, in lieu of 
wei 
First, having écinterbalinted the body exactly, ascertain 
how many parts of water will cause it to sink in water ; next, 
how many parts will cause it to sink in the liquid, whose gra- 
vity is to be ascertained. ©'The number last found, being di- 
vided by the first, the quotient is the specific gravity. 
Supposing that the graduation be made to correspond with 
the size of the bulb, so that 1000 parts of pure water will just 
sink the bulb in another portion of the same fluid ; the pro- 
cess for any other liquid, will be, simply i ascertain how 
many parts of water will sink the the globe The number 
observed: will be the specific gravity ; so that. recourse ie wa- 
ter, or to calculation, would be unnecessary.” 
The rationale of this last mentioned process, is 
the case of ascertaining the gravity of liquids, by coins 
stopple, weighing 1000 grains.—(See page 123.) 
To find the Che gravity of a Mineral, without cateula- 
n, and without degrees 
The preceding igre represents a balance. employed in 
this. © respects, more convenient than 
common. ss The moveable, weight on one of the arms, 
renders it easier to counterpoise bodies of various weights ; 
