This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
The precise gradations of activity, between the virulence of the metal in its perfect metallic state, and its indolence in that of a perfect calx, are not well known; but thus much is certain, that it continues extremely active till the calcination is almost complete. When crude antimony is roasted over a gentle fire and kept constantly stirring, till the cessation of the fumes shews the sulphur to be dissipated, the metal remains in form of a greyish-white powder, so far calcined, that on being urged with a strong fire, it melts into a dark yellowish red glass, no part of it resuming its metallic form. Never-theless, both the calx and the glass are very virulent emetics; differing, however, from the metal itself, in this, that their active parts are soon exhausted by repeated infusion in vegetable acids (b), whereas the metal, so far as the experiment has been carried, seemed to lose nothing of its power.
The activity of the metal is restrained like-wife by the combination of sulphur with it. Crude antimony, a natural mixture of it with sulphur, is altogether mild; doses of half a dram, or a dram, for the most part, only gently loosening the belly, or promoting insen-sible perspiration: the greater degree of tenuity the powdered mineral is reduced to, the more considerable are its effects; and the case appears to be the same in regard to all the antimonials that are not totally dissoluble in the animal fluids.
(a) Malouin, chemie medicinale, part iv. chap, 50.
(b) Boerhaave, elem. chem. process. 210.
Vitrum an-timonii Ph. Ed.
Antimonium vitrificatum Ph. Lond.
If a part of the sulphur of the antimony be separated, by such operations as do not calcine the metal, the remaining mass proves pro-portionably more active. Hence, as different sorts of crude antimony, and different parts of one and the same mass, hold manifestly different proportions of sulphur, it is probable that they vary in degree of activity.
The sulphur of antimony is separated by deflagration with nitre: the greater the quantity of nitre, to a certain point, the more of the sulphur is consumed, and the more does the metal, thus diverted of its corrector, exert its virulence. An increase of the nitre, beyond the quantity which is sufficient to separate the sulphur, renders the products, contrariwise, milder and milder; by more and more calcining, or destroying the powers of, the metal itself.
Thus, antimony deflagrated with one eighth its weight of nitre, is said to act chiefly, in doses of fifteen or twenty grains, as an alterative or diaphoretic: with one sixth its weight, it vomits and purges, for the most part very mildly, in doses of eight or ten grains: with half its weight, it vomits strongly, in the quantity of from one to five or six grains; and with equal its own weight †, it proves, in the same doses, a most violent emetic, operating as it were in-exhaustibly, till its whole substance is expelled. All these preparations are of a dark red or yellowish red colour, and hence perhaps their name of crocus or saffron. The three first are taken from the fire as soon as the deflagration ceases; ceases: the last, which is the officinal crocus is kept for fome time in fusion, during which a whitish saline scoria rises to the surface, which is separated when the mass grows cold.
Crocus anti-monii medi-cinalis.
Crocus anti-monii mitior committ. of Lond. col. † Crocus an-timonii Ph. Lond. & Ed. metallorum vulgo: He par antimonii quibusdam.
The last of the above proportions of nitre, to wit, equal the weight of the antimony, seems to be nearly that by which all the sulphur is destroyed, and the metallic part left bare. If the nitre be increased to twice the weight of the antimony, the metal itself is so far calcined by it, as to appear, after the deflagration, white; and if now freed from the saline matter by ablution with water, proves so mild, as to occasion only some light nausea and gentle vomiting, with a large discharge of saliva and thick urine. If the antimony be treated in the same manner with thrice its weight of the salt, it becomes a perfect indolent calx, the same with that obtained by calcining the pure metal with nitre.
In this deflagration, a part of the nitre is changed by the sulphur into a neutral salt simi-lar to that prepared from pure sulphur and nitre deflagrated together, that is, to the nitrum vitriolatum: this salt may be recovered from the water in which the calx is washed, by filtration, evaporation, and crystalization. A part of the nitre becomes likewise an alkaline salt, which, as formerly observed, renders a part of the metallic calx dissoluble: the cry-stallized salt is found to retain a little of this calx, but cannot be expected to receive from thence any particular virtues.
The Edinburgh college, in their last pharmacopoeia, direct the grey calx of antimony, as prepared for making the glass, to be calcined for an hour with equal its weight of nitre, and Emeticum mite anti-monii Boer-haave. Antimonium calcinat. Ph. Lond. Anti-mon. diapho-ret. uulgo. Anodynum minerale Ph. Brand.
Calx anti-monii nitrata Ph. Ed.
and the mixture then to be washed with warm water till it becomes tasteless.