618
Extracts.
part in.
EXTRACTA SIMPLICIORA. Dub. Simple Extracts.
" All simple extracts, unless otherwise ordered, are to beprepared according to the following rule.
" The vegetable matter is to be boiled in eight times itsweight of water, which is to be reduced by boiling to one half;the liquor is then to be expressed, and after the feces havesubsided, to be filtered, and evaporated by the heat of boilingwater, until it begins to thicken; and is to be, finally, inspis-sated by a medium heat, frequently stirring, until it acquiresa consistence proper for forming pills.
" All extracts, when they begin to get thick, ought to befrequently stirred with a clean iron spatula. They may bereduced to a proper degree of thickness by means of a stoveheated for the purpose.
" They ought to be preserved as much as possible from thecontact of the air; and the softer ones are to be sjirinkled withrectified spirit."
EXTRACTUM CACUMINUM ABSYNTHII. Dub.Extract of Ifbrmwood. z
This is ordered to be prepared according to the above direc-tions. It is nearly a simple bitter, the volatile oil being dissipatedduring the evaporation. It may be used in those cases for whichbitters are commonly prescribed; but it is scarcely ever used.The dose is from gr. x. to 9J. taken three times a day.
EXTRACTUM ACONI'TI. Lond. Extract of Aconiteor Wolfsbane*
they are collected, must be revived by immersing their stalks in water for twelve oreighteen hours. Such as perfectly recover by this means, which will be known by theleaves becoming as fresh as when growing, are to be bruised and pressed ; and the juicefrom them passed through a fine hair sieve, and immediately placed on the fire. Sometime before it is raised to the boiling temperature, a quantity of green-coloured matterbegins to float on the surface of the fluid : in the juice of some plants this matur is veryconsiderable: it is to be carefully removed by means of a thin perforated tin dish.By the time the liquor boils, or soon afterwards, the green matter ceases to appear.The boiling is to be continued until rather more than half the fluid has been evaporated,when the decoction is to be put into a conical pan, and suffered to stand in it untilcold. A large precipitation of dark green-coloured feculent matter will then be foundto have taken place; from which the supernatant fluid is to be poured off, and againexposed to evaporation, until half of it is consumed; when it is to stand for precipitation.< c The precipitated matter from the second coction is by no means so green as thefirst. The remaining fluid is now to be suffered to boiJ till it acquires the consistence ofsyrup; when the matter which had been collected at the commencement by filtrationand precipitation is to be mixed with it, and placed in a metallic pan in a water-bath,and further evaporated till of the consistence of an extract. In this latter part of theprocess, the operator must give his constant attention until it be quite completed. It isnot necessary that the matter should be kept constantly stirred; but the operator oughtnever to suffer it to stick, a become hard on the sides of the pan ; for, if it be allowedto harden, the extract loses its green colour ; and in proportion to such loss is the de-terioration of its medicinal virtues." London Medical Repository, vol. iv. p. 198.i Extrait d'Absynthe (F.) Wermuth-extrakt (G.) Estratto d'Assenzo (/.)» Extrait d'Aconit (F.) Eisenhiitlein-extrakt (G.) Estratto d'Acouito Napello {I.)