TANNING MATTER, &C. 1^ 



white wax of the shops, which is sold in the form of small Experiments, 



round cakes. It formed with sulphuric acid a thick black &c- on an arti- 



, , J. ^.,, J , ncial substance 

 magma, and was not acted upon by cold distilled water having the cha- 



when washed with it upon a filter. Upon being digested racter of tan- 

 with alcohol in a sand-bath, a brownish solution was ^'"S matter- 

 formed, which upon cooling became very turbid, andap* 

 peared as if filled with a white flocculent substance. The 

 same operation was repeated with different portions of 

 alcohol until this ceased to act. The whole of the solu- 

 tions in alcohol were then mixed, a large quantity of dis- 

 tilled water was added, and the alcohol was separated by 

 distillation. 



On the surface of the remaining liquor, when cold, a 

 white crust was formed, which being separated, was found 

 to possess the properties of spermaceti, and weighed 18 

 grains. The filtrated liquor Avas then evaporated to a 

 small quantity, became of a pale brown colour, and was 

 rendered turbid by solution of isinglass. 

 Anhnat Fat, 



This experiment was made upon the kidney fat of veal, 

 but I cannot take upon me to assert that the results would 

 have been the same with every kind of fat. One hundred 

 grains of it with one ounce of concentrated sulphuric 

 acid, after some time, formed a blackish soft mass: a 

 second ounce of sulphuric acid was then added, and the 

 whole was digested and occasionally heated during nearly 

 three months. Six ounces of distilled water were poured 

 upon the black pulpy mass, and formed a thick uniform 

 liquid, which, after digestion for six or seven days, was 

 when cold filtrated. The liquor which passed was of a 

 brown colour, and upon evaporation became black, 

 leaving a considerable portion of a blackish substance v 



upon the filter, which was added to that which had been 

 collected by the first filtration. The whole was washed 

 with cold water, which passed colourless. Boiling water 

 was then poured upon the filter, by which a considerable 

 portion wa3 rapidly dissolved, and a brownish-black so- 

 lution was formed, which copiously precipitated gelatine. 



The residuum on the filter was then dried, and being 

 collected, was digested in alcohol, which dissolved the 

 greater part. 



The solution in alcohol was filtrated, but (apparentfy 



Vol. XV.-~Sept. 1806. D by 



