The presence of very minute quantities of vermilion may, according to Mr. Smithson, be detected by the following simple experiment. Boil a portion with sulphuric acid in a platina spoon, and lay the sulphate thus produced in a drop of muriatic acid, on a piece of gold, and then bring a piece of metallic tin in contact with both, when the white mercurial stain will be produced.
Antimony.
Although the ancients were entirely ignorant of this metal, they were well acquainted with several of its combinations,[[297]] Basil Valentine, a German Benedictine Monk, was the first who described the process for obtaining it from its ore; to this work, originally written in high Dutch, and known by the title of the “Currus Triumphalis Antimonii,” which was published towards the end of the 15th century, we are indebted for almost all our knowledge respecting this metal.
Antimony is of a greyish white colour, having considerable brilliancy; its texture is laminated, and exhibits plates crossing each other in every direction; its specific gravity is 6·7021; when rubbed upon the fingers it communicates to them a peculiar taste and smell; it is very brittle, and fuses at the temperature of 809°, but does not appear to be volatile; when fused, with the access of air, it emits white fumes, consisting of an oxide of the metal, which formerly was called Argentine flowers of Antimony. When the metal is raised to a white heat, and suddenly agitated, it enters into a state of combustion, and is converted into the same white coloured oxide.
According to Thenard,[[298]] antimony is susceptible of no less than six different degrees of oxidation; Proust, however, has shewn that they may all be reduced to two, viz. protoxide and peroxide. The former of which alone exerts any sensible activity upon the human body; but this constitutes the basis of several preparations, which although in common use for medical purposes, are so extremely poisonous in larger doses, as to render them objects of interest to the forensic physician.
Emetic Tartar.[[299]] Tartarized Antimony.
This saline body appears in the state of white crystals, whose primitive figure is the regular tetrahedron, although it assumes a variety of secondary forms. Its chemical composition is still involved in some obscurity; it is stated, in the different dispensatories, to be a triple salt, consisting of tartaric acid, oxide of antimony, and potass, and that it ought therefore, according to the principles of the reformed nomenclature, to be termed a Tartrate of Antimony and Potass. The truth of these views, however, we have already[[300]] ventured to question; Gay Lussac has stated that in the various metalline compounds of which Super-tartrate of Potass is an ingredient, this latter substance acts the part of a simple acid; an opinion which receives considerable support from the great solvent property of cream of tartar, and from the striking fact that it is even capable of dissolving various oxides which are insoluble in tartaric acid, of which the protoxide of antimony is an example. In such a state of doubt, a better name could not be found than that of tartarized antimony.
The salt, according to Dr. Duncan, is soluble in three times its weight of distilled water at 212° Fah. and in fifteen, at 60°.
When it is heated red hot in an earthen crucible, it blackens, and undergoes decomposition like a vegetable body, leaving a residuum of metallic antimony, and slightly carbonated potass.