Gonji derations on Vegetable Extracts, $&* 



We may give an idea of the variety of the fubftances which 

 are, or may in general be contained in pharmaceutic ex- 

 tracts, by presenting thofe which have been found in the fap, 

 juices, inhifions, and deco&rons of vegetables. 



Before the interefting analyfis of feveral kinds of fap by 

 Deyeux and Vauquelin, chemifts were far from imagining 

 that liquors fo limpid, and in appearance fo iimple, were for 

 much compounded as they really are. 



The above celebrated chemifts found in them the carbonic 

 and acetous acid ; acetites and carbonates of potafh and lime ; 

 muriate, fulphate, nitrate of potafh, &c. 



The lap of the vine and horn- beam tree fumifhed a vegeto- 

 animal matter. 



That of the oak and beech-tree prefented gallic acid, tan- 

 ning principle, and two forts of extracts. 



That of the birch and maple gave a very abundant faccha- 

 rine matter. 



Of thefe different fubftances discovered in fap, and of thofe 

 which exift in the exprefled juices of frefh herbaceous plants^ 

 in thofe of fruits, in the infufions and decoctions of dried 

 plants, and of all the folid parts of vegetables, we may, with 

 fufficient foundation, form the following lift : 



lit, Mucous matter or mucilage : it is obtained from feeds 

 mfufed in water; there are fome plants which contain it in 

 great abundance, for example the mallows : 



It oozes from the bark of feveral trees under the name of 

 gum. •. 



2d, The acid mucous matter : it exifts in lemons> oranges> 

 granadillos, &c. 



3d, The acid and faccharine mucous matter : it is con- 

 tained in apples, pears, grapes, &c. 



4th, Sugar : it is found in feveral roots, in the fap of certain 

 trees ; it ifiues under a fluid form from the bark of fome of 

 them, and becomes condenfed ; it bears the name of manna: 

 it exifts in the gramineous ftems, very little ;n the leaves, 

 almoft always in the ftate of ne£tar, of honey, or mucofo- fac- 

 charine matter. It abounds in fruits, and is not perceptible 

 in the feeds until they have experienced germination, and 

 particularly in berries. The fugar-cane and maple give it 

 pure and cryftallized. 



It is difficult to obtain it in the dry ftate from other vege- 

 tables either, becaufe it is much more embarraffed by the 

 mucilage, acid, and extractive matter, &c. whether it exifts 

 in them under a different modification or in a ftate of imper- 

 fection. 



5th, Mucous matter combined with a rtfin ; it may be 



diftin^uilhed 



