68 Confideratlojis on Vigetahh ExtraSls, 



nth. The dry extracts of La Garaye are all made by fimpTe 

 maceration evaporated in a balneum mariie, or in a fiove, ou 

 ibit di(hes; ihev form very thin Icales. 



La Garaye filtered his liquors a lecond time when thev 

 were half evaporated; but this fecond filtration is ufelefs if 

 there exifls no depofit, and it is hurtful if there be one ; be- 

 caufe in feparating it, inllead of fullering it to be redilToIved, 

 the extra6l accjuircs the property of attrailing moiflure more 

 ftrongly. 



The procefs employed by La Garaye for preparing his cx- 

 iraAs alters as little as poffible the fubllances they contain, 



t2th. Extrafts made from fuch freih -gathered roots as 

 contain mucous bodies in Hates of fblution and of infolu- 

 bility, that is to fay, mucilage, properly called ftarch, alio 

 have need, as already faid, of a preliminary preparation to 

 make them lofe the latter fubllancc, capable of becoming 

 mouldy when by the aid of warm water it has aflbmed the 

 Hate of Jelly. 



But this ftarch does not hurt extrafts prepared with infu- 

 fions or deco6tions of the fame roots dried, becaufe the mu- 

 cilage of the roots is deftroycd or moditled by the deficcation. 



jath. Sc-vcral pharmacopolifls having obferved this change 

 which deficcation produces in the ftate of the mucous part 

 of plants, have thought that it would be of advantage to 

 prepare extrafts from dried plants, efpecially in regard to 

 plants hiiihly mucilaginous, fuch as burrage. 



Experience has taught them that extrafts more abundant, 

 and which keep longer without alteration, may be obtained 

 by this method. 



Is the extractive principle increafed by deficcation at the 

 cxpenfc of the mucilage, or does the mucilage by drying in 

 the plants atlume a ftate which approaches very near to that 

 of extrartive miUter ? 



34th. There are fome extrafts in which it is neceffary to 

 retain a refmo-o;ummy or extrafto-refinous fubftance : this 

 mav be eftec^edljy fucceflively treating the plant which con- 

 tains it with water and with alcohol. The refult of thefe 

 two folutions, IfUimately mixed and properly concentrated, 

 gives this kind of cxtraft. 



i)th. Somi times wine Is employed in order to have only 

 one'infufion to make, and to fulfil the fame indication ; but 

 it is probable that the end propofcd in this cafe is not ob- 

 tained. 



Wine, indeed, befides its not difiblvlng fo well the two 

 required principles, is attended with the inconvenience of 

 furnifliinsr not only the extractive fubflauce proper to it, but 



alfo 



