Crystal of Tartar combined with the reguline Part of Antimony. Stibiated or Emetic Tartar.
Pulverize and mix together equal parts of the Glass and of the Liver of Antimony. Put this mixture, with the same quantity of pulverized Cream of Tartar, into a vessel capable of containing as much water as will dissolve the Cream of Tartar. Boil the whole for twelve hours, from time to time adding warm water, to replace what is dissipated by evaporation. Having thus boiled your liquor, filter it while boiling hot; evaporate to dryness; and you will have a saline matter which is Emetic Tartar.
OBSERVATIONS.
The Glass and Liver of Antimony are no other, as was said in its place, than the metallic earth of Antimony separated from the redundant Sulphur of that mineral; but still retaining such a quantity of phlogiston as to possess, excepting its metalline colour, nearly the same properties with Regulus of Antimony, and especially its emetic quality, and its solubility in Acids. Indeed these two preparations seem to have more of an emetic quality than the Regulus itself, and therefore are employed preferably to all others in the preparation of Emetic Tartar.
It is not yet ascertained in which of the principles of Antimony its emetic virtue resides. We are sure, however, that it cannot be ascribed to its earthy part: for the calx of Antimony, when entirely deprived of all phlogiston, is not emetic, nor even purgative; as is evident from the effects of Diaphoretic Antimony and the Pearly Matter.
Some authors think Antimony contains an arsenical principle, to which they impute its emetic quality; nor is their opinion altogether void of probability. For this arsenical part seems to be indicated by several of the properties of Antimony, and particularly by its affinities with other metallic substances, in which it very nearly resembles Arsenic. But this doth not amount to a positive proof: for we can draw nothing but probable conjectures, at most, from such analogies.
Other Chymists think the emetic virtue of Antimony depends on the union of its metallic earth with its phlogiston. This opinion seems to me much more probable than the other: for by only recombining a phlogiston with the earth of Antimony, deprived by calcination of all its emetic virtue, that virtue is perfectly restored, and the Regulus thus revivified is no less emetic than that which never underwent calcination.
However this be, it is certain that Cream of Tartar acquires an emetic quality, not by barely uniting with one of the principles of Antimony, but by dissolving entirely the reguline, or semi-reguline, part thereof; and that its emetic quality is so much the stronger, the more of that substance it hath dissolved. This is the result of several experiments made on the subject by Mr. Geoffroy.
That gentleman collected several parcels of Emetic Tartar, having different degrees of strength. "I employed," says he[15], "an ounce of each of those Emetic Tartars: I rubbed them separately with an equal weight, or something more, of a black flux, made of two parts of red Tartar, and one part of Nitre calcined together. These mixtures I put into different crucibles, formed like inverted cones: I kept them in a melting heat till the Salts in fusion sunk, and appeared like a smooth oil at the bottom of each crucible. I then let the fire go out, broke the crucibles when cold, and found the resuscitated Regulus in a mass at bottom.
"Out of one ounce of the weakest Emetic Tartars I obtained from thirty grains to one dram eighteen grains of Regulus. From one ounce of such as were of a middling strength I got one dram and an half; and the most violent yielded me two drams and ten grains.