470 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



ity with raw fat, a sieve-like, perforated disk of stone-ware is 

 to be laid upon the surface of the pot, and 10 per cent, of ex- 

 tremely diluted and chemically pure hydrochloric acid add- 

 ed, in a proportion of three pounds of the acid (of 1.12 spe- 

 cific gravity) to 100 pounds of water. The vessel is then to 

 be covered with a well-ground and tightly-fitting stone-ware 

 top. By heating, the fat is melted in the cells, the membra- 

 nous walls of which are dissolved by the diluted acid, allow- 

 ing the fat to escape, which rises above the disk, this at the 

 same time gradually sinking toward the bottom. All the 

 membranous, unmelted portions are carried down under it 

 and accumulate at the bottom with the dilute acid. 



When all the fat is melted and all the membranous por- 

 tions destroyed, the acid liquid is to be let off and the fat 

 washed two or three times with hot water. (This acid gelat- 

 inous solution can be converted into an excellent manure by 

 the addition of a powdered phosphorite.) A small quantity 

 of carbonate of masrnesia is to be added in the last washing:, 

 so as to neutralize the acid. The fat, thus washed, is next 

 dissolved in its volume, or less, of Canada oil (a petroleum), 

 in the course of which the water and nitrogenous animal sub- 

 stances are removed, and may be separated by decanting. 

 The clean fatty solution may then be introduced into a tinned 

 copper distilling apparatus, and the solvent again recovered 

 by distillation. The resulting fat will be completely free 

 from smell, taste, and color, and is absolutely neutral, con- 

 taining no trace of water or nitrogenous substances, on which 

 account it can be kept without change for years. Although 

 this method is somewhat tedious, it is yet effective; and, 

 taking into consideration the much greater quantity of fat 

 extracted and its greater purity, its economy will be amply 

 vindicated. 14 (7, CCL, 203. 



LIQUID SOAP FOR CLEANING WOOL. 



An excellent liquid soap for cleaning and washing raw 

 wool, according to Moser, may be prepared by using a kettle 

 in which the mass can be heated, by means of a steam-tube 

 opening directly into it. The kettle (holding one hundred 

 and fifty gallons) is first to be half filled with water, which is 

 then to be heated, and sixty-eight pounds of caustic soda of 

 42 B., and one hundred and twenty-five pounds of oleine 



