U8 BESIXS, BITTEE FEI NCI PEES, ETC. 



mass treated with 50 per cent, spirit, iu Avhicli a little brown 

 resin Avas found to be insoluble. To the alcoholic solution ether was 

 added, and then sufficient water to cause separation. On well 

 shaking the ether dissolved the whole of the mongumic acid, the 

 addition of a few drops of acetic or hydrochloric acid facilitating 

 solution. The mongumic acid was then obtained by evaporating 

 the ethereal liquid. 



h. Treatment of the mixed resins irith a solution of soda or potash in 

 dilute spirit, and recovery of the resin by the addition of acetic or 

 hydrochloric acid and filtering, or, if very finely suspended, 

 shaking Avith ether. I adopted this method in separating a resin- 

 acid from pteony-seed.^ The mixed resins Avere treated with 

 boiling 85 per cent, spirit, and the liquid kept at 0° for some time, 

 to allow of the separation of a little resin anhydride that had 

 been carried into solution. To the filtrate water was added till 

 the spirit was reduced to a strength of 50 per cent., by which the 

 resiu Avas precipitated. The mass Avas then dissolved in a solu- 

 tion of soda in 50 per cent, spirit, again precipitated by the 

 addition of acid, and finally decolourized in alcoholic solution by 

 animal charcoal. In adopting this method the requisite strength 

 of the spirit must be ascertained by preliminary experiments. 



c. Treatment of the mixed resins with aqueous soda or iMash. — 

 Any resin dissolved l)y the alkaline liquid may be generally re- 

 covered by acidification Avith acetic or hydrochloric acid. (Com- 

 pare also § 45)." It is, moreover, not xmfrequently possible to 

 obtain sparingly soluble combinations of the resin with siher, leadj 

 barium, calcium, etc., by adding salts of those metals to the ^cAw- 

 tion of resinatc of soda. This method is sometimes successful in 

 cases of mixtTircs of several resin-acids or of a resin-acid Avitli other 

 resinous substances solul)lc in solution of soda. The i-esins present 

 may be separated l>y fractional precipitation ; or it may happen 

 that only one is precii)itated by the salt used, in Avhich case, of 



1 Archiv d. Pharm. [3], ix. l-JB, 1S70 (Journ. Cniem. Soc. xxxvi. 1043). 



- Chrijmn, discovered by Piccard in thu Inids of the poplar (Ber. d. d. ehem. 

 Ges. vi. 884, 1873; Journ. Chem. Soc. xxvi. ]'236) might be isolated by this 

 method. It is precipitated yellow by acids, is somewhat sparingly soluble in 

 ether and alcohol, and almost insoluble in petroleum, bisulphide of carbon, 

 chloroform, and benzene. The latter, when warm, removes the so-called 

 tectochrysin. An alcoholic solution of chrysin is coloured violet by ferric- 

 chloride, and gives with neutral acetate of lead a yellow precipitate, soluble in 

 excess and in glacial acetic acid. 



