=229. Specific Gravity.=—The specific gravity of sirups and molasses can be determined by the spindle in the usual way, but in the case of molasses which is quite dense, the spindle method is not reliable. It is better, therefore, both in molasses and massecuites, to determine the density by dilution. For this purpose, as described by Spencer, a definite weight of material, from 200 to 250 grams, is dissolved in water and the volume of the solution completed to half a liter. A portion of the solution is then placed in a cylinder and the quantity of total solids contained therein determined in the usual way by a brix or specific gravity hydrometer. In case 250 grams of the material be used the calculation of the brix degree for the original material is conducted according to the following formula: G × _B_ × _V_ _x_ = -------------. _W_ In the above formula _x_ is the required brix degree, _V_ the volume of the solution, _B_ the observed brix degree of the solution, and G the corresponding specific gravity obtained from the table on page 73. When only small quantities of the material are at hand the hydrostatic balance (=53=) should be employed. For this purpose twenty-five grams of the material are dissolved in water and the volume of the solution made up to 100 cubic centimeters. The sinker of the hydrostatic balance is placed in the solution and equilibrium secured by placing the weights upon the arm of the balance in the usual manner. Since the arm of the balance is graduated to give, by direct reading, the specific gravity, the density can be obtained at once. _Example._—Let the position of the weights or riders upon the balance arm be as follows: (1) at point of suspension of the bob = 1.000 (3) at mark 7 on beam = 0.07 (4) at mark 9 on beam = 0.009 Specific gravity = 1.079 The nearest brix degree corresponding to this specific gravity (=58=) is 19. The total weight of the solution is equal to 100 × 1.079, _viz._, 107.9 grams. Since the solution contains nineteen per cent of solid matter as determined by the hydrostatic balance, the total weight of solid matter therein is 107.9 × 19 ÷ 100 = 20.5 grams. The total per cent. of solid matter in the original sample is therefore 20.5 ÷ 25 × 100 = 82 and the specific gravity corresponding thereto (page 74) is 1.42934. The specific gravity of a massecuite may also be determined in pyknometers especially constructed for this purpose.[186]