A dispensatory, or commentary on the pharmacopoeias of Great Britain : comprising the natural history, description, chemistry, pharmacy, actions, uses, and doses of the articles of the materia medica / by Robert Christison.

  • Robert Christison
Date:
1848
Catalogue details

Licence: Public Domain Mark

Credit: A dispensatory, or commentary on the pharmacopoeias of Great Britain : comprising the natural history, description, chemistry, pharmacy, actions, uses, and doses of the articles of the materia medica / by Robert Christison. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    ALCOHOL and ETHERS. In all distillations of alcoholic or etherial fluids, the apparatus described in the hist page, is greatly superior to the ordinary re- tort and receiver. The rapidity with which the operation may be carried on without loss is much greater than by any other method. Under the head of sulphuric ether, a description and figure will be found of the apparatus for preparing this fluid by means of a con- tinuous supply of rectified-spirit. In the present place, it may be well to notice the arrangement of the apparatus for preparing ni- tric ether according to the process in the Edinburgh Pharmacopoeia. It consists of a mattrass nr, such as that represented in page li. an exit-tube h c, for the etherial va- pour, which is condensed in a re- frigeratory, and a safety-tube, ef g, which is filled with nitric acid before the operation begins, and which must be so placed as to leave the point e about an inch above the fluid in the mattrass. With such an arrangement, and a little sand in the bottom of the mattrass, nitric W -S acid may be poured upon rectified- spirit with perfect safety at inter- vals, and a strong hyponitrous ether obtained without any risk of explosion. (See Aether nitrosus.) ALKALIS. No general observations seem necessary under this head. ALKALOIDS. The Vegetable Alkaloids may be obtained by a variety of pro- cesses ; which invariably however comprehend decomposition of the alkaloidal salt in the crude drug, either by the superior affinity of an alkali, earth, or alkaline carbonate, or by double decomposition with some compound salt, whose base forms an insoluble salt with the acid in the drug. Active neutral principles, such as narcotin from opium, piperin from white pepper, picrotoxin from cocculus- indicus, and elaterin from claterium, may be obtained through the agency of such simple solvents as water, rectified-spirit, and sul- phuric ether, used singly or successively. But no alkaloid can be thus detached. The solutions, from which vegetable alkaloids are prepared, are in general obtained best by the method of percolation, or dis- placement. Some experience is required to apply this process in all cases with success. But, when well performed, it is greatly su- perior in general to every other mode of extracting the active mat- ters of vegetable drugs, when the liquid used is spirituous or ethe-
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