Carbonate of sodium should be kept in well-closed vessels. Large, colorless, monoclinic crystals, rapidly efflorescing in dry air, and falling into a white powder, odorless, having a sharp, alkaline taste, and an alkaline reaction. Soluble in 1.6 parts of water at 15° C. (59° F.), in 0.09 part at 38° C. (100.4° F.), and in 0.25 part of boiling water; insoluble in alcohol. Commercial sodium carbonate contains water in varying proportions. Its solutions should, therefore, be regulated by the hydrometer. A solution of 10 per cent, of the hydrous commercial carbonate of sodium, specific gravity 1.038, or of 5 per cent., specific gravity 1.019, at 15° C, or better of one per cent., specific gravity 1.003, may be kept in stock. In winter time a strong solution separates crystals; it is, therefore, better to prepare a solution for all temperatures of five or one per cent. Dissolve five or one part of the salt in 95 or 99 ounces of distilled water, and filter the solution. Proportion 100 to 5 or 100 to 1. Or dissolve for immediate use.

Sodium Chloride (NaCl; 58.5.) - White, shining, hard, cubical crystals, or a crystalline powder, permanent in the air, odorless, having a purely saline taste, and a neutral reaction. Soluble in 2.8 parts of water at 15° 0. (59° F.), and in 2.5 parts of boiling water; almost insoluble in alcohol. Chloride of sodium (table salt) is found in a great many of the natural mineral waters. An aqueous solution must be perfectly clear and colorless. The salt is generally dissolved for immediate use; however, a ready-made solution may be prepared by dissolving one part of the salt in nine parts of distilled water (10 per cent.). Specific gravity 1.073 at 15° C. Proportion 10 to 1.