1824.] Scientific Notices — Chemistry. 305 



4. Note on the pretended Alkali of the Daphne. 

 By M. Vauquelin. 



In 1808, when analyzing the thymelea alpina and gnidium, I 

 perceived an alkaline matter, which I described as follows : — 

 " Taste, pungent and very permanent ; very volatile ; acts on 

 vegetable colours, like the alkalies." At that time, however, as 

 the existence, of an alkali of a vegetable nature was unknown 

 (M. Seguin's discovery of such a substance in opium having 

 been forgotten, as it were, till 1816), I did not venture to affirm 

 that it was really a vegetable alkali; and I did well. 



Since the experiments of M. Sertuerner have been known in 

 France, and MM. Pelletier, Boullay, Lassaigne, and other 

 chemists, have found new alkaline substances in various vegeta- 

 bles, I have thought it right to resume my labours on this sub- 

 ject. The following are the results of my researches. 



Before I detail the properties of this pretended alkali, I shall 

 describe the best processes for obtaining it pure. 



First Process. — v Pour one pound of boiling water over one 

 pound of dried daphne thymelea (spurge laurel?), and digest the 

 mixture at a temperature between 140 and 160° for some hours. 

 Strain off the liquid, and press the residuum to obtain the whole 

 of it, and having added to it a little lime, or potash, or even 

 magnesia, submit it to distillation, carrying the process as far as 

 possible without burning the residuum. 



The distilled liquid is as colourless as water, very pungent, 

 chiefly affecting the throat, has a very irritating smell, and 

 quickly restores the blue colour of litmus previously reddened 

 by an acid. If it be wished to have this principle in a more 

 concentrated form, sulphuric acid in slight excess may be 

 added to the infusion above-mentioned, the liquid reduced by 

 careful evaporation to one-fourth, or even one-eighth of its 

 original bulk, and an excess of magnesia then added to it, and 

 distilled to dryness in a water bath, taking care to keep the 

 receiver cool. This product will be four or eight times as strong 

 as the former. 



Second Process. — Make a hot infusion of the bark of the 

 daphne thymelea in four parts of pure alcohol. Digest it in a 

 close vessel at the temperature of 96° for three or four hours, 

 after which decant off the brownish coloured liquid. 



Distil till no more alcohol comes over; let the residuum 

 cool, and decant the liquid to separate it from a resinous matter 

 which falls down during the distillation of the alcohol ; wash 

 the residuum with warm water, and add the washings to the 

 decanted liquid. 



As the resin carries down with it a large quantity of the pun- 

 gent principle, it must be heated, sufficiently to melt it, in water 

 acidulated with sulphuric acid, and this liquid must be added to 

 New Series, vol. vm. Jt 



