Butter of zinc, obtained by distilling to dryness the muriate of
zinc, was found to consist of exactly equal parts of the two ingredients.
The fuming butter of arsenic was found to contain nearly 60 chlorine to 40 arsenic. This compound has the property of dissolving phosphorus when gently heated, but to part with it on being cooled. It also readily dissolves sulphur when warmed, and yields crystals of sulphur by cooling. It likewise dissolves resins, oil of turpentine, or olive oil; and in these respects resembles the compounds of sulphur or phosphorus with chlorine, which have the same property of entering into combination with fixed and volatile oils.
In this respect also the butter of antimony was found to agree with the same compounds; and in the proportion of its constituent parts, to be as nearly as possible the reverse of the preceding.
It is remarked concerning these compounds, in general, of metals with chlorine, that their volatility or fusibility are in no degree cor- respondent to the qualifies of the metals of which they consist. One of the compounds of iron, for instance, is volatile; but those of bismuth, zinc, and lead, are even less fusible than the metals themselves.
In order to correct the preceding analysis, the author has had recourse to the general analogy of definite proportions; and since one of hydrogen unites with 7'5 oxygen, or with 33'6 chlorine, the compounds of chlorine have been compared with the oxides of the same metals; and in the instances of copper, iron, zinc, and arsenic, have been found to agree correctly with the analyses of oxides by other chemists; and where such agreement has been wanting, it has been obtained by new analyses of the oxides of tin, lead, antimony, and bismuth.
In making similar comparisons of the compounds of the same metals with sulphur, four instances of correspondence were found in tin, lead, antimony, and bismuth; but others were observed not to accord with the proportions assigned.
The author concludes with observing the degree of analogy that subsists between the oxides of metals, and their compounds, with chlorine; horn silver, resin copper, horn lead, and corrosive sublimate, being each soluble in excess of muriatic acid, although the last is even less soluble in nitric or sulphuric acids than in mere water.
In the description of the author's former experiments on the same subject, he entered more into the detail of particular occurrences than he now thinks necessary. He was formerly apprehensive that the operations of the same poison might not be always the same, and was
