cannot well be collected,—evaporate the liquid to dryness, char it by means of nitric acid and chlorate of potash, as directed for copper (p. 357), boil the carbonaceous mass for half an hour in a mixture of eight parts of hydrochloric acid and one of nitric acid, and introduce the filtered solution into the modification of Marsh's apparatus for detecting arsenic described in page 204, but without the tube e h. Kindle the gas at e, and try whether a black, dull stain, not removable by solution of chloride of lime, be produced on a surface of porcelain held across the flame. If no stain be produced, there was no antimony in the liquid under examination. If the porcelain be stained, apply the heat of a spirit-lamp flame to the tube d e. Antimony will de deposited within the tube where the heat is applied. In order to ascertain its nature, break the tube, heat the portion containing the crust with nitro-hydrochloric acid, evaporate to dryness, dissolve the residue in hydrochloric acid, decompose a part of this solution with water, and subject the rest to a stream of hydrosulphuric acid gas, which will produce the usual orange sulphuret of antimony.
3. If antimony be not indicated in either of these ways in the fluid part of the subject of analysis, the solid portion may next be subjected to the second process; but success will very seldom attend the search when the previous steps have failed.
The first branch of this process,—a slight modification of Dr. Turner's,—is a very delicate and satisfactory method of detecting antimony in organic mixtures. Some practice is required to transmit the hydrogen gas with the proper rapidity. The gas ought to be allowed to pass for some time before the spirit-lamp flame is applied, otherwise the oxygen remaining in the apparatus may cause an explosion, or will oxidate the metallic antimony, formed by the reduction of the sulphuret. As soon as the reduction of the sulphuret begins, the tube is blackened on account of the action of the sulphuretted-hydrogen on the lead contained in the glass. This obscures the operations within the tube; but on subsequently breaking it, a metallic button or a sublimate will be easily seen. When the sulphuret is considerable in quantity and the gaseous current slow, the metal remains where the sulphuret was; but if the mass of sulphuret is small and the current rapid, then the metal is sublimed and condensed in minute scaly brilliant crystals.
The second branch of the process is a modification of the method lately employed by Professor Orfila for detecting antimony in the textures and secretions of animals poisoned with tartar-emetic. It is probably more delicate than the other, but not more satisfactory.
The method of analysis here recommended, as well as every other yet proposed for organic mixtures, merely detects the presence of antimony. It does not indicate the state in which the metal was combined. It is a process in short for antimony in every state of combination.
It is almost unnecessary to observe that when the contents of the stomach or vomited matters are the subject of analysis, care must be taken to ascertain that tartar-emetic was not administered as a remedy.
