Ozone

This is supposed to be oxygen in an allotropic and more active state. It is formed by putting into a wide bottle pieces of clean phosphorus, with a little water, so that the phosphorus shall be partly in the water and partly uncovered. Close the bottle for some hours, when the air it contains, will manifest the odour and effects of ozone.

Sulphurous Acid Gas

Sulphurous Anhydride. It is procured in a nearly pure state by heating 2 parts of quicksilver with 3 of oil of vitriol, and collecting the gas over mercury. By passing the gas through a tube surrounded with a freezing mixture, it is condensed into a liquid. For ordinary purposes, the gas may be obtainedas directed under Acid,Sulphurous.

Purified Gelatin

Grenetine. It is made by various processes from gelatinous animal matters. Nelson's Patent Gelatine is made from cuttings of the hides of beasts, and skins of calves. These, freed from hair, flesh, fat, etc, are washed and scored, then macerated for 10 days in a ley of caustic soda, and afterwards placed in covered vessels at a temperature of 60° to 70° until they become tender; then washed from the alkali, exposed to the vapour of burning sulphur until they become sensibly acid, dissolved in earthen vessels heated to 150°, strained, put into settling vessels heated to 100° or 120° for nine hours, the clear liquor drawn off, and poured on the cooling slabs to the depth of 1/2 an inch. When cold, the jelly is cut in pieces, washed till free from acid, redissolved at 85°, poured on slabs, cut up, and dried on nets.

Gelatin Bone

The bones are boiled to remove the fat, then digested in dilute hydrochloric acid till the earthy matter of the bone is dissolved. The gelatin, which retains the form of the bone, is washed in a stream of water, plunged in hot water, and again in cold, to remove all remains of acid, and sometimes put into a solution of carbonate of soda. When well washed, it is dried on open baskets or nets. By steeping the raw gelatin in cold water, dissolving it in boiling water, evaporating the jelly, and cutting it into tablets, it may be dried and preserved in that form.

German Paste, for feeding insectivorous singing-birds. Blanched sweet almonds 1 lb., pea meal 2 lbs, butter 3 oz., saffron a few grains, honey q. s. Form the whole into a paste, and granulate it by pressing it through a cullender. Some add the yolks of 2 eggs.

Gilding

Leaf gold is affixed to various surfaces, properly prepared by gold size or other adhesive medium. Metallic surfaces are coated with gold, by means of amalgam of gold and mercury, applied with a wire brush, wet with an acid solution of mercury (made by dissolving 10 parts of mercury in 11 of nitric acid, by a gentle heat, and adding 2 1/2 parts of water). The article thus coated is heated over charcoal till the mercury is dissipated, and afterwards burnished. To give it a redder colour, it is covered with gilders' wax (a compound of verdigris, ochre, alum, and yellow wax); again exposed to heat, and afterwards washed and cleaned by a scratch brush and vinegar. An inferior kind of gilding is effected by dissolving gold, with a fifth of its weight of copper, in nitro-hydrochloric acid, dipping rags in the solution, drying and burning them, and rubbing the ashes on the metallic surface with a cork dipped in salt and water.