[412]. The roman poets constantly use it in the plural number, which evidently shews that it was meant to denote other kinds of poisons, or poisons in general; thus Juvenal in the first satire, v. 156.
“Qui dedit ergo tribus patruis Aconita, vehetur
Pensilibus plumis,——”
So again Ovid in the first book of Metamorph, v. 47.
“Lurida terribiles miscent Aconita novercæ.”
[413]. Theophrastus tells us that a poison may be prepared from aconite so as to occasion death within any definite period; see page [183] in the present volume.
[414]. See an account of this process of preparing extracts in vacuo, in Medico-Chirurg. Trans. vol. x, p. 240; and for a history of their superior powers, the author begs to refer the reader to an account of the articles in his Pharmacologia.
[415]. Pharmacologia, vol. 1, p. 136.
[416]. Med. Observ. and Inquiries, vol. v. p. 317.
[417]. It may be obtained from opium by the following process, invented by Robiquet. Three hundred parts of pure opium are to be macerated during five days, in one thousand parts of common water; to the filtered solution, fifteen parts of perfectly pure magnesia (carefully avoiding the carbonate) are to be added; boil this mixture (A) for ten minutes, and separate the sediment (B) by a filter, washing it with cold water until the water passes off clear; after which, treat it alternately with hot and cold alcohol (12, 22. Bé) as long as the menstruum takes up any colouring matter; the residue is then to be treated with boiling alcohol (22, 32, Bé) on cooling, the solution will deposit the Morphia in crystals.