416 Pharmaceutical Preparations. Part IIL

termitted in the night: fillingup the veffel with water in pro-portion to the evaporation; andfcraping the bottom with awooden fpatula from time totime, to get off the fedimentwhich begins to precipitate afterfome days digeftion. The fedi-ment needs not to be taken outtill the boiling is finifhed, atwhich time the liquor is to beftrained when cold, and eva-porated to an extraft, of a dueconfidence for being formed intopills.

The author Qbferves, that bykeeping the liquor ftrongly boil-ing, the tedious procefs may beconfiderably expedited, and the fixmonths digeftion reduced to fourmonths : that in the beginning ofthe digeftion, a thick, vifcous,oily matter rifes to the top, andforms a tenacious fkin as the li-quor cools; this is fuppofed to beanalagous to efletitial oils, thoughwanting their volatility : that theoil begins to difappear about theend of the firft month, but ftillcontinues fenfible till the end ofthe third, forming oily clouds asoften as the liquor cools : that therefm at the fame time fettles tothe bottom in cooling, prefervingfor a long while its relinous form,but by degrees becoming pow-dery, and incapable of being anylonger foftencd, or made to cohereby the heat; that when the pro-cefs is finifhed, part of it ftill con-tinues a perfedl refin, difloluble infpirit of wine, and part an indif-foluble powder: that when thedigefted liquor is evaporated toabout a quart, and fet in the coldtill next day, it yields a brovvnilhearthy-faline matter, called theelTential fait of opium, in figurenearly like the fedative fait ob-tained from borax, intermingled

with fmall needled cryftals. Hegives an accouut of his havingmade this preparation fix or feventimes. The vefTel he made ufe ofwas about two inches and a halfdiameter in the mouth : the quan-tity of water evaporated was abouttwenty-four ounces a day, andfrom a hundred and thirty to ahundred and forty quarts duringthe whole digeftion. Out of fix-ty-four ounces of opium, feven-teen ounces remained undifiolvedin the water: the quantity of re-finous matter, precipitated duringthe digeftion, was twelve ounces :from the liquor, evaporated to aquart, he obtained a dram of ef-fential fait, and might, he fays,have feparated more ; the liquorbeing then further evaporated toa pilular confiftence, the weightof the extraft was thirty-oneounces.

It is fuppofed, that the narcoticvirtue of opium refides in the oilyand refinous parts; and that thegummy extradl, prepared by theabove procefs, is endowed withthe calming, fedative, or anodynepowers of the opium, diverted ofthe narcotic quality as it is of thefmell, and no longer productiveof the diforders, which opiumitfelf, and the other preparationsof it, frequently occafion. A cafeis mentioned, from which the in-nocence and mildnefs of the me-dicine are apparent; fifty grainshaving been taken in a day, andfound to agree well, where thecommon opiate preparations couldnot be born. But what fhare itpoffefles of the proper virtues ofopium, is not fo clear ; for thecure of convulfive motions of theftomach' and vomitings, whirhat length happened after theextract had been continued dailyin the above dofes for feveralyears (plujiturs annecs) cannotperhaps