Page:Proceedings of the Royal Society of London Vol 1.djvu/305

Rh portions of 50, 30, and 20, he thinks it no great violation of probability, to suppose that experiments affected with no error would, in fact, have given these integral results instead of the former decimal parts.

Mr. Smithson proceeds further to express his doubts, not only of the existence of quadruple. but even of strictly triple compounds. He believes that all combination whatever is binary, and is inclined to consider the present compound as consisting of equal parts of galena. and fahlertz; the latter being also a binary compound of the sulphurets of antimony and of copper, in the proportion of three of the former to two of the latter.

The author next computes the proportion of the four ultimate elements; and these, being deduced from assumed simple fractions, are simply as the numbers 12, 25, 15, and 8. These, he remarks, are sexagesimal parts of this ore, as were those also which in a former paper be assigned to calamine. -

When in that communication he offered a system founded on the results of his own experiments, he is apprehensive that he may have been sppposed to be inﬂuenced, even unconsciously to himself, by a favounte theory; but the present case he thinks not liable to the same objection, since no fondness for theory affected the experiments of Mr. Hatchett, which nevertheless accord with its principles When viewed in a proper light.

Mr. Smithson, conceiving it established that chemical compounds consist of elements united in simple proportions by weight, observes, that greater accuracy is to be expected from correct theory than can be obtained in chemical experiments.

The principles of his theory require that simple ratios should always obtain in binary compounds; and he gives instances from the subjects of the foregoing experiments, Which any chemist can, by careful repetition, conﬁrm.

The ratios which he assigns to the compounds of lead are such, that two parts of lead make three of sulphate of lead, and ﬁve of lead make six of sulphate of lead. So also ﬁve of antimony make six of sulphnret, and three of antimony make four of powder of algaroth.

From the only crystalline form which Mr. Smithson believes to exist of the triple sulphuret, he infers that its primitive form is a cube, and not a tetrahedral prism, as stated by Count Boumon; and he observes, that the angles given by the Count are at variance with each other.

Though much important information has resulted respecting the formation of this acid, from the experiments of Hermbstadt. Westrumh, Barthollet, Fourcroy, and Vauqueliu. the properties of it have been rather ucglected since the original dissertation of Bergman, to whom