_By the Balance._
Take a bit of glass rod, note its loss when weighed in water and in the liquid under trial. Divide the latter by the former, the quotient will be the s. g. of the liquid. Thus a glass rod loses in water 171 grs., in alcohol, 143 grs. 143/171 = .836. s. g. of the alcohol.
_Specific Gravity bottles._
These are made to hold 100 or 1000 grs. of pure water at 60, and are accompanied by a counterpoise. It is only necessary to fill the bottle with the liquid to be tested. Counterpoise and weigh; the weight in grains will be the s. g. Oily and viscous matter should never be introduced into the s. g. bottle. In case the s. g. bottle is not at hand any light flask will do. Make a file mark on the neck, counterpoise it, fill to the mark with pure water at 60, note the weight of the water. Empty, dry thoroughly and fill with the liquid to be tested; the weight of this divided by that of the water = s. g.
Are instruments for determining the specific gravity of liquids by noting the depth to which a stem sinks. They consist of a cylinder with a weight beneath it to make it float upright, and a graduated stem. When intended for liquids lighter than water, the 0 or point at which they float in pure water at 60 is at the lower point of the stem, and as the liquid is lighter they sink more deeply; for liquids heavier than water the 0 is at the top of the scale. Many are graduated according to their proposed use, as alcoholometers, lactometers, sacharometers. (see DISTILLATION). The graduation most employed is that of Beaume. Excellent hydrometers with the degrees and the true s. g. on the same stem are made by dr. W. H. Pile of Philadelphia.
_To Convert Degrees Beaume into Specific Gravity._
1. For liquids heavier than water - Subtract the degree B. from 145, and divide into 145, the quotient is the s. g.
2. For liquids lighter than water - Add the degree B. to 130, and divide it into 140. The quotient is the s. g.
To Convert Specific Gravity into Degrees Beaume.
1. For liquids heavier than water.--Divide the s. g. into 145, and subtract from 145. The remainder is the degree B.
2. For liquids lighter than water.--Divide the s. g. into 140 and subtract 130 from the quotient. The remainder will be the degree B.
_Table of Specific Gravity._
Mercury 13,600 Lead 11,325 Copper 9,000 Cast Brass 8,000 Steel 7,850 Wrought Iron 7,780 Cast Iron 7,207 Tin 7,300 Marble 2,690 Common Stone 2,520 Brick 2,000 Soil 1,974 Coal, anthracite1,640 Coal, bituminous1,270 Sand 1,620 Sea-water 1,030 COMMON WATER 1,000 Oak, (dry) 925 Ash 800 Maple 755 Elm 600 Yellow Pine 660 White Pine 554 Cork 249 Carb. Acid 1.9 Air 1.25 Coal Gas 0.6 Hydrogen 0.0848
The specific gravity in table also represents the number of ounces in each substance in 1 cubic foot / 16 = lbs.
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