580 Confederations on Vegetable Extracts. 



A figure and a more extend ve description of the botanical 

 characters of the aya-pana will be found in the firft number 

 of the Plantes du Jar din de la Maimaijbn, which will appear 

 in a few months. 



P. S. I have received from madame Bonaparte a quantity 

 of the dried leaves of the aya-pana, which 1 have delivered 

 to citizen Alibert, phyfician to the hofpital of St. Louis, pro- 

 feffor of the materia medica, to determine, by experiments, 

 its medical properties. 



LXIV. General Confederations on Vegetable Extracts. By 

 C. Parmentier *. 



M. 



ODERN chemifts have denoted under the name of 

 extract) or rather that of extractive matter , and placed among 

 the number of the immediate materials of vegetables, a fub- 

 fhmce the diftinguifhfng characters of which, when in its 

 ftate of purity, are : it is foluble in water ; after a proper eva- 



J)oration of the juices, or of the decoction which held it in 

 blution, it becomes a (olid transparent body, and, when the 

 evaporation has been too rapid, an opake mafs, more or lefs 

 infoluble ; in both cafes k is coloured, and has a favour al- 

 ways acid, and more or lefs bitter, acrid, or harfh. 



They have found alfo in extractive matter the property of 

 combining with alkalies; of ftrongly attracting oxygen; of 

 being precipitated by acids, alum, metallic folutions, and 

 oxides; and of being able, with the help of mordants, to. 

 adhere to fluffs like the colouring part of vegetables. 



The medicines known in pharmacy under the name of 

 extracts do not exhibit this extractive matter pure and un- 

 mixtd, as it ought to be in order to be chemically examined. 



Extracts are productions obtained by the evaporation of 

 juices or infufions, or the decoctions of plants under different 

 degrees of confidence, from that of honey to the dry -or pul- 

 verulent ftate. 



They are often very compound mixtures, which contain, 



1 ft, All the immediate materials of vegetables which the 

 water can carry with it, whether naturally ioluble, or whether 

 they acquired that property both by the help of caloric and 

 the reciprocal action which they exercife on each other. 



2d, All the combinations which thefe immediate materials 

 can form with each other during the evaporation. 



3d, AH the foluble refulls of the decompofitions they have 

 experienced. 



* From the Annates de Cbimie, No. 127. 



We 



