Smalts

See Pigments.

How To make Skeleton Leaves

Steep the leaves, seed-vessels, or other parts of the plant to be dissected, in rain water, until the whole of the soft matter is decomposed. Some require a few weeks, others several months. The rotted parts are now to be carefully removed by a fine brush, under the surface of water, or in a stream of water. A syringe is sometimes required. To bleach the skeletons soak them for some hours in a mixture of 1 oz. of strong solution of chloride of lime and a quart of distilled water. Lastly, wash thoroughly in cold water, and dry by exposure to air.

Smoking Fluid

One drop of creasote in a pint of water imparts a smoky flavour to fish or meat dipped into it for a few minutes.

Soap

Fob Perfumed and Toilet Soaps, see Skin Cosmetics, further back. For the manufacture of soaps generally, see Dr. Ure's ' Dictionary of the Arts,' Wagner's 'Chemical Technology,' and other similar works. Hard soaps are made by boiling oils or fats with a ley of caustic soda. Soft soaps consist of oil and potash; and as they do not separate from the ley like the hard soaps, they generally contain an excess of caustic alkali. Silica soap has silicate of soda incorporated with it. Soap is adulteratcd by earthy matters, as pipe-clay, etc.; these and other impurities remain when soap is dissolved in alcohol.

Marine Soap

Patent. This is made by substituting cocoa-nut oil for the fats and oils used in the manufacture of common soap. It has the advantage of forming a lather with salt water.

Soda

For its medical and pharmaceutical compounds, see Pocket Formulary.

Hyposulphite of Soda

Dissolve 1 lb. of crystallized carbonate of soda in a quart of boiling water. Slake 1/2 lb. of lime in another quart of water. Mix the solutions, let them stand in a covered vessel until cold, pour off the clear liquid, and boil it with more sulphur than it will dissolve. Pour off the clear solution into a deep vessel, and pass sulphurous acid gas through it until it becomes nearly colourless. While still a little yellow, filter,and evaporate it quickly in an earthen vessel to a syrupy consistence. Shake this with half its bulk of rectified spirit, and allow the lower layer to crystallize under the alcoholic solution which floats on it. It must be kept from the air and light.

Solvents for Gutta Percha

Benzol readily dissolves it. So do chloroform and bisulphide of carbon.

Solvent toe Old Putty and Paint

Soft soap mixed with solution of potash or caustic soda; or pearlash and slaked lime mixed with sufficient water to form a paste. Either of these laid on with an old brush or rag, and left for some hours, will render it easily removable.

Soluble Glass

See Glass.

Solution's used in Electrotype Mantpulations, etc.

Solution for Soldering

Dissolve zinc in hydrochloric acid to saturation, add pulverized sal ammoniac, and boil for a short time. Applied with a sponge or feather it facilitates the flow of the solder.