1521. Benzoated Lard

1521.    Benzoated Lard. Take benzoin in coarse powder, 1 ounce; fresh lard, 1 pound. Heat together for 2 or 3 hours in a water-bath, and then strain.

1522. To Bleach Lard

1522.    To Bleach Lard. Lard may be bleached by applying a mixture of bichromate of potassa and muriatic acid, in minute proportions, to the fat. (See Nos. 1509 (Engelhardt's Method of Bleaching Palm Oil) and 1523, also No. 537.)

1523. To Bleach and Harden Tallow

1523.    To Bleach and Harden Tallow. In a copper boiler, put 1/2 gallon water, and 100 pounds rendered tallow; melt over a slow fire, and add, while stirring, 1 pound of oil of vitriol, previously diluted with 12 of water; afterwards, 1/2 pound bichromate of potassa, in powder; and lastly, 13 pints water, after which the fire is suffered to go down, when the tallow will collect on the surface of the dark green liquid, from which it is separated. It is then of a fine white, slightly greenish color, and possesses a considerable degree of hardness. (See No. 1509 (Engelhardt's Method of Bleaching Palm Oil).)

1524. Factitious or Imitation Spermaceti

1524.    Factitious or Imitation Spermaceti. White spermaceti, 10 parts ; sonorous cake stearine, 20 parts; potato starch, 5 parts; mucilage, 1 part. Melt the first three and unite well, then let the mass cool to the consistence of dough; turn it out on an oiled marble or lead slab, and roll it into a cake; next sprinkle a little mucilage on it, double it, and roll again; repeat the process as often as required ; lastly allow it to cool. If it has

PETROLEUM, OR CRUDE COAL OIL been properly managed, it will flake when broken up, and resemble spermaceti.

1525. Extraction of Fat from Bones

1525. Extraction of Fat from Bones. A process has been adopted abroad for extracting oil and fat from bones and other animal refuse, by digesting it in a closed and heated vessel with benzole or similar hydrocarbon. After a few hours the liquid is drawn off, the hydrocarbon separated by distillation, and the oil is left ready for use. The bones may then be used for the manufacture of gelatine. This is very similar to a method lately proposed of obtaining oil from oleaginous seeds, but in this latter case, as would probably be preferable in the former, bisulphide of carbon is the menstruum employed.