This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Euphorbium: a gummy resinous concrete juice; exuding from an oriental, prickly, lactescent shrub, of the same name, euphorbia (officinarum) aculeata nuda multangularis: aculeis geminatis Linn. spec. plant. The juice is brought immediately from Barbary, in drops or tears of an irregular form; some of which are found, on being broken, to contain little thorns, twigs, flowers, and other vegetable matters; others are hollow, without any thing in the cavity: the tears are in general easy to break, of a pale yellow and sometimes of a gold colour on the outside, and white within.
Euphorbium, applied lightly to the tongue, discovers a sharp biting taste; held for some time in the mouth, it proves vehemently acrimonious, inflaming and exulcerating the parts. The finer dust which flies off in pulverization, unless great care is taken to avoid it, is apt to affect the operator's head and throat in a violent manner.
It consists of about equal parts of resinous and gummy matter. The acrimony resides chiefly in the former; the spirituous tincture being excessively fiery, and when infpiffated still more so; whereas the watery infusion and extract are bitterish with only a flight, though a very durable acrimony. A single drop of a strong spirituous tincture produces in the mouth a sensation of burning, which, as Cartheufer observes, is scarcely to be obtunded by mucilages or oils in less than an hour. It gives over nothing in distillation either to water or spirit.
The extreme acrimony of this drug renders it absolutely unfit for any internal use: several correctors have indeed been proposed for abating its virulence, but the best of them are not to be trusled to. It is employed only, and that but seldom, for external purposes; in stimulating unguents and plasters for paralytic limbs, carious bones, etc. Some have ventured on a minute portion of it, mixed with other powders, as an errhine, in obstruclions of the nostrils, and mucous disorders of the head; a practice by no means advisable, as we are in no want of medicines for these purposes, equally effectual, and far more safe. I have seen violent and dangerous inflammations produced by rashly using even very small quantities of it mixed with snuffs.