ON ARTIFICIAL TANNIN. 361 



astringent, and bitter taste: it precipitated gelatine copi- 

 ously, and adhered strong'y to animal substances, which it 

 dyed of a saffron colour: it was more soluble in hot water 

 than in cold : it was dissolved by potash, and this com- 

 pound at the expiration of some days had deposited a small 

 quantify of detonating matter. It was readily soluble in 

 concentrated nitric acid, and in alcohol. I analysed it in 

 the following manner. 



4. a. I took 40 parts, that I had dried in a capsule with a Analysis of it. 

 gentle heat, boiled them in distilled water, and added in three 

 portions 30 parts of carbonate f lead. Effervesence took 

 place. After an hour's boiling, I filtered. 



b. A pulverulent matter, of the colour of bistre, remained 

 on the paper, which, being washed with cold water, acidu. 

 lated with sulphuric acid, yielded sulphate of lead, a liquor 

 containing some resin, and a small quantity of the two 

 amers. 



c. The filtered liquor (a) was decomposed by sulphuric 

 acid. The sulphate of lead being separated, the liquor was 

 concentrated : and a little oily matter was deposited, which 

 had either escaped the action of the carbonate of lead, or 

 was regenerated during the evaporation. The liquor sepa- 

 rated from the oily matter, and concentrated farther, left 

 a thick, very bitter, and astringent matter, that precipi- 

 tated gelatine. This was divided into two portions, No. 1, 

 and No. 2. 



d. No. 1 was mixed with potash, which coagulated it 

 almost into a mass. It was then diluted with cold water, 

 and filtered. On the filter was left a deep yellow powder, 

 not crystallizable, and susceptible of detonation, but less 

 so than the compound of amer at a maximum and potash. 

 The aqueous solution of this powder reddened sulphate of 

 iron at a maximum, and precipitated gelatine, when the al- 

 kali had been previously saturated with an acid This yellow 

 powder was a compound of potash, amer at a minimum, and 

 amer at a maximum : for, having decomposed it by muri- 

 atic acid, I obtained by spontaneous evaporation, 1st, 

 crystals of amer at a minimum retaining a little amer at a 

 jnaximum ; 2dly, a mother water, which, being saturated 

 with potash, yielded a detonating substance in small yellow 



needles, 



