Mohr's Lute

Mix equal parts of brickdust and litharge, and beat them into a paste with linseed oil. Apply this with a stiff brush, and dust it over with coarse sand: dry it in a warm place.

For Cements for plugging teeth, see Teeth and Mouth Cosmetics, further back.

Charcoal

Wood charcoal is made by burning wood with only a partial access of air. For chemical purposes, that made in iron cylinders, in the manufacture of wood vinegar, is preferred.

Aluminized Charcoal

This is recommended by Dr. Sten-house as a cheap and very efficient decolorizing agent. Dissolve in water 54 parts of the sulphate of alumina of commerce, and mix with 92 1/2 parts of finely powdered wood charcoal. When the charcoal is saturated, evaporate to dryness, and heat to redness in covered Hessian crucibles till the water and acid are dissipated. The charcoal contains 7 1/2 per cent. of anhydrous alumina.

Charcoal from Coal-tar

Heat gently in an iron pot 1 lb. by weight of coal-tar pitch till it melts. Add 2 lbs. of fluid coal-tar, and mix. Stir in 7 lbs. of hydrate of lime in very fine powder. The thick mass is now roasted, stirring all the time, till it is reduced to a fine powder. It is then ignited in a covered crucible till all the vegetable matter is carbonized. The charcoal when cold is digested with dilute hydrochloric acid, and finally washed with water in a filter, and dried. Dr. Stenhouse recommends this as an admirable form for decolorization. For such liquids as decoction of logwood it is four times as efficient as animal charcoal. Chameleon Mineral. Mix equal weights of black oxide of manganese and pure potash, and heat them in a crucible. Keep the compound in closely stopped bottles. A solution of it in water passes through various shades of colour from green to red.

Chemique, or Chemic Blue - Sulphate of Indigo

To 7 or 8 parts of oil of vitriol, in a glass or earthen vessel, placed in cold water, add gradually 1 part of fine indigo in powder, stirring the mixture at each addition with a glass rod, or piece of tobacco-pipe. Cover the vessel for 24 hours, then dilute with an equal weight of water. Sometimes it is sold without diluting. The German (Nordhausen) fuming acid answers best, 4 or 5 parts of it being sufficient for 1 of indigo. For dyeing silk, etc, carbonate of potash, soda, or ammonia, is added, to neutralize the acid, taking care not to add it in excess.

Chloralum

Chloride of aluminium is made by acting on alumina, the basis of clay, with hydrochloric acid, and evaporating to form crystals. Under the above name it is extensively used as a disinfectant and deodorizer, decomposing sulphuretted hydrogen and coagulating albumen.

Chlorate of Baryta

Saturate solution of chloric acid, (see further back) with fresh precipitated carbonate of baryta, filter, and crystallize.

Chlorate of Potash

Liebig. Dissolve chloride of lime in water, add solution of chloride of potassium, and boil to dryness. Dissolve the mass in hot water, and filter if necessary: on cooling, a large quantity of chlorate of potash is deposited. For another process, see PotassAe Chloras, Pocket Formulary.