1729. Properties of Charcoal

1729.    Properties of Charcoal. This article, when fresh, possesses the property of taking lime and other saline matter from syrups and other aqueous solutions, especially organic ones, at the same time that it decolors them. As a decolorizer and deodorizer, animal charcoal (prepared from bones) is vastly superior to vegetable charcoal. Charcoal should be fresh burnt and fresh powdered and preserved from contact with the air. Unless these precautions be observed it rapidly loses its valuable qualities. (See No. 1752 (To Prepare Animal Charcoal to Decolorize Vinegar and other Vegetable Liquids).)

1730. Aluminized Charcoal

1730.    Aluminized Charcoal. This is recommended by Dr. Stenhouse as a cheap and very efficient decolorizing agent. Dissolve in water 54 parts of the sulphate of alumina of commerce, and mix with 921/4 parts 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 just 71/2 per cent, of anhydrous alumina.

1731. Charcoal from Coal-Tar

1731.    Charcoal from Coal-Tar. Heat gently in an iron pot till it melts, 1 pound coal-tar pitch. Add 2 pounds fluid coal-tar, and mix. Stir in 7 pounds 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.