Conjiderathns on Vegetable Extra£!s. 67 



flannel, and evaporates it in a balneum maiice. When he 

 wifhes to make it more trnnquilii/ing than narcotic, he iiib- 

 jecls it to both the tullowing preparations : 



The firft confifts in cutiing the opium into flices, boiling; 

 it in the quantity of water ntceflary to diffolve every thing 

 foluble it contains, draining the liquor, evaporating it to a 

 half, putting it into a tin cucurbit immeiTed in a fund bath 

 over a fire maintained three months night and day, adding 

 water in proportion as it is evaporated, fcraping from time to 

 time the bottom of the evaporating veffel, to prevent the refm 

 which is precipitated from being burnt, ftraining the liquof 

 when three months arc elapfcd, and then evaporating. 



A folid cxtraft, called opium, is obtained by long digef- 

 tioii of all the cxtiafts of opium : this is the one mod 

 efteemed by Baume. The fccond procefs is that employed 

 by JoflTe to extraft the gluten from the farina of wheat. 



The opium is expofed under the cock of a veHcl which 

 produces only a fmall ftream of water, where it is kneaded : 

 its extraftive matter is diflblved, and the refinous part re- 

 mains In the hands ; the liquor is then filtrated, and it is 

 evaporated to the confiftence of exti»a6t. 



The third method of correfting opium is that recom- 

 mended by Baume for freeing the extract of coloquintida 

 from the prejudicial refin which it contains, viz. folution, 

 cold filtration, and evaporation. But as the refin oi opium 

 is more difficult to be removed than that of coloquintida, 

 ihefe three operations arc repeated fix times fucceflively. 



8th. It is cuftomary to purify by folution and filtration ex- 

 trafts of the acacia, hypocillis, cachou, and liquorice, lold 

 in the (hops. But an exaft pharmacopolift will prefer pre- 

 paring the laft-mentioncd article himfelf from the liquorice 

 of our gardens : he will treat it by infufion, and will thus 

 obtain a brown cxtraft of a fweet talle and very agreeable, 

 while the otiicr is black and acrid, and often contains char- 

 coal and always copj)cr, both taken from the bottom of the 

 bafon by fcraping it with an iron fpatula. 



9th. Extradt of feima ouwht to be made from an infufion 

 of the leaves: ftrong decoction would add to the extraiHivc 

 fiibftance civcn by infufion, a mucilaginous matter which 

 would weaTcen its virtue. 



10th. Extracts of hemlock, flramonium, hyofcyamns, and 

 bcUa-dona, were prepared by Storck from the uiipurilicd 

 juices of thefe jilants. 



It is much belter to evaporate thefe juices after they have 

 been purified and mixed at the end oi the baking, the green 

 fecula being feparated. 



Ea iilh. 



