104 



«oluble in alcohol, but scarcely or not in watei-. Nitrate of 

 silver produces in the alcoholic solution of hederate of ammonia 

 ii white precipitate, which dissolves in hot alcohol and subsides 

 on cooling in a crystalline state. 



Hedera -Tannic Acid. In the seeds of Hedera Helix. Is 

 obtained from the seeds, exhausted successively with ether and 

 with alcohol (to be used for the preparation of hederic acid), by 

 boiling with water. Mix the decoction with acetic acid and 

 acetate of lead, remove the precipitate and throw down the liquid 

 with ammonia. The beautiful yellow precipitate is slightly 

 washed (being soluble), afterwards decomposed under water with 

 sulphuret of hydrogen and the solution filtered. The liquid yields 

 on evaporating the acid but in an impure state. — Inodorous, 

 amorphous, acid substance, the solution of which colours the 

 salts of iron-oxyd dark-green, but does not precipitate glue. 



Helenin = Cie H14 O 5 . In the root of Inula Helenium. 

 Exhaust with alcohol, and mix the tincture hot with three times 

 its volume of water. It becomes cloudy, and the Helenin 

 subsides slowly in a crystalline form. — Forms white, friable, 

 quadrangular prisms and needles of faint smell and taste, 

 insoluble in water, readily soluble in alcohol and ether; fuses at 

 75°, boils at 275° to 280° under partial decom])osition, dissolves in 

 concentrated sulphuric acid with red colour, which becomes 

 slowly darker. 



[According to K alien, Helenin is resolvable into two crystal- 

 Usable substances, for one of which he retains the name Helenin rr 

 C12 Hg O2. It is devoid of odoiir and taste, fusible at 110°. The 

 other is Alant-camplior=:C20 Hie Oo, with a smell and taste sug- 

 gestive of peppermint; fuses at 64°; yields cymol by distillation 

 with phosphorus-pentasulphide. ] 



Heliunthic Acid^Cu Hg Og. In the seeds of Helianthus 

 annuus. Exhaust the seeds, freed from the husks, with hot 

 alcohol, distil off the latter from the tincture, filter the residue, 

 precipitate the liquid with acetate of lead, decompose the washed 

 precipitate under water with sulphuret of hydrogen, filter and 

 evaporate the liquid. — Brownish-yellow, amorphous mass, friable 

 to a slightly coloured powder, fusible by heat ; dissolves readily in 

 water and alcohol, not in ether; imparts a splendid dark-green 

 colour to chloride of ii'on, which changes to violet on addition 

 of ammonia; does not precipitate glue. 



Helleborein=:::C52 H44 O30. One of the two glucosids of the 

 root of Helleborus niger and H. viridis, and present in larger 

 qviantity than the other. It is obtained by boiling with water, 

 precijiitating with subacetate of lead, removing the excess of lead 

 by sulphate or phosphate of soda, evaporating, precipitating with 



