ANALYSIS OF HEDGE HYSSOP. 365 



VII. 



Analysis of Hedge Hyssop, Gratiola Officinalis, of the 

 Order Bignonia of Jussieu: by Mr. Vauquei-in*; 



JL HE experiments, of which I am about to gire'an account, Object of the 

 were instituted for the purpose of ascertaining the nature of ""^^"^ 

 the purgative principle of hedge hyssop. 



1. The expressed and filtered juice of this plant has but The expressed 

 little colour, compared with that of many other vegetables. ■'"'^^' 



Its taste is acrid and bitter. It is rendered very slightly 

 turbid, by heat, or by aqueous infusion of galls, which in- 

 dicates, that it contains but a very small portion of animal 

 matter. It has also but little acidity f . 



2. Subjected to distillation, it yielded a water void of DistiHed, 

 taste, and in which nothing was detected by a considerable 

 number of tests. It contains, therefore, no principle, that 



is volatile at the temperature of boiling water. 



3. The juice being evaporated to the consistence of an Extract treatedi 

 extract, and treated with alcohol, the greater part dissolved withalcohoL 

 in it. That which did not, was higher coloured than the 

 other, and insipid, or with very little taste : a proof, that this 

 property pertains to the part soluble in alcohol. The alco- 

 holic solution, being evaporated to dryness, left a brownish 

 yellow substance of extreme bitterness. 



This substance, being treated with water, imparted to it Alcoholic ex- 



a pretty deep brown colour, and a bitter taste; leaving a *'^^"^'^^^^'* 

 r J I 7 > » with water. 



soft substance, drawing out into strings like a resin, and 

 the taste of which, at first sweetish, was afterward extra- 

 ordinarily bitter. Though this substance appeared to be 

 insoluble in water, yet it dissolves in a large quantity of this 

 fluid when heated. 



The alcohol therefore had dissolved two substances from Two substances 

 the extract of hedge hyssop, a resin, and a matter soluble c's-tractedby th« 



*Ann.deChim. Vol.LXXII, p. 191. 



f In plants that contain an acrid principle there is generally 

 little or no animal matter ; as if these substances were incompatible, 

 ^r the circumstances favourable to the formation of the one were 

 ■ not suitable for the formation of tiie other. 



