The ordinary tables of alcoholic strengths at 15.56° are given in the section on "Alcohol-ometry." The following data, due to Osborne, McKelvy, and Bearce,8 allow of the specific gravity of aqueous alcohol mixtures being calculated for any temperature between 10° and 40°.

1 Phil. Trans., 1847, 249. 2 Phil. Mag., 1848, 22, 123.

3 Gilb. Anna!.., 1811. 4 Pogg. Ann., 1869, 138, 230.

5 Trans. Chem. Soc, 1902, 81, 717.

6 Arkiv Kern. Min. Geol, 1906, 2, No. 24.

7 Ephemeris, 1884-5; Pharm. J., [iii], 1884, 15, 44, and 1885, 16, 147-8.

8 Bull. U.S. Bureau of Standards. Scientific Paper No. 197.

The specific gravity of alcohol at 25° was found to be 0.78506 gram per c.c.

The specific gravity of various mixtures of alcohol and water was determined at 10°, at 40°, and at each interval of 5° between these temperatures. From the results, the values of the coefficients in the following equation were calculated: by weight.

A = D25 + a(t - 25) +β (t - 25)2 + y(t . 25)3.

Here Dt is the specific gravity at any temperature t° between 10° and 40°, and D25 is the specific gravity at 25°. The values of the coefficients a, β, and γ are given in the following table.

With the aid of this table and the following one giving an extended range of alcohol percentages, the specific gravity of any mixture of ethyl alcohol and water, at any temperature between 10° and 40°, can be calculated from the foregoing equation.