But though the strong proofs of the poison of antimony, drawn from its natural history and chymical analysis, should be rejected by prejudice or scepticism, yet the easy transition of this mineral, by the simplest processes and slightest accidents, from a salutary medicine to a deadly poison, has not yet, been seriously denied.
It is found by chymists generally to contain mercury, arsenic, lead, sulphur, and sometimes copper, silver, and other metals[48]. When it is melted by fire, or deflagrated with half its weight of nitre, it becomes a poison. But if antimony, or its regulus, is mixed with an equal portion of common salt, and calcined with a gentle heat, stirring it constantly, and afterwards washing it with pure water, it becomes a gentle diaphoretic.
The mildest preparation of antimony; its white calx, which may be safely taken to the quantity of some drachms, if melted with an equal portion of nitre, a little powder of charcoal, and a small quantity of animal fat, is immediately rendered poisonous.
If antimony is melted with a fourth part of salt of tartar, a salutary medicine is obtained; but if the same process is performed with two or three times that quantity of the salt, so nice is the management of this wonderful mineral, in place of a medicine it becomes a poison[49]
When antimony is combined with other medicines, as it frequently is by practical physicians, unless the composition is directed with chymical skill, it may be so changed, or, in the language of the chymists, decomposed, as totally to alter its usual qualities.
By marine acids the activity of antimonials is increased, and they are rendered corrosive, or virulently emetic and purgative; but by the addition of the nitrous acid this virulence is diminished or destroyed, and they become mild diaphoretics[50].
Such being the uncertainty and variety in the operation of antimonial preparations, it cannot be improper, since they are now in common family use, to lay before the public the objections against the general application of them, which arise from the accurate observations of the best chymists, and most experienced physicians; since it is not improbable, that many who deal them out with a liberal hand, and with the most charitable and benevolent intentions, would dread the danger of a drug, which though published as an infallible remedy, may, without great skill and precision in the direction of it, in place of a remedy become a poison.