By a suitable course of experiment, the proportions of the several salts present were found to be nearly thus :
| Sulphate of potash | . 71 |
| Sulphate of soda | 19 |
| Mnriate of soda. | 5 |
the remainder consisting of a little muriate of ammonia, mixed with the muriates of iron and copper.
In the part which remained undissolved by water, there was also found to be submuriate of copper, similar in composition to the green sand of Peru, and a yellow powder that was judged to be submuriate of iron; so that, on the whole, this single mass presented as many as nine different species of matter.
In the Bakerian lecture for 1808, the author had supposed fluor acid to be decomposed when potassium is heated in silicated fluoric acid gas, and that oxygen was separated from it; an inference which had also been drawn from a similar experiment by Messrs. Gay- Lussac and Thenard. But when he afterwards found that oxymuriatic acid could not be decomposed, and that no oxygen could be separated from the compounds of this body with phosphorus, sulphur, or the metals, he was led to conceive an analogy between the oxymuriatic and fluoric compounds, an analogy also suggested to him by M. Ampere.
The experiments described in the present paper are principally guided by this analogy, with a view to ascertain whether it is well founded.
The subjects of experiment are silicated fluoric gas, originally dis. covered by Scheele. Liquid fluoric acid in its concentrated state, first obtained by Messrs. Gay-Lussac and Thenard, and the fluo—boric acid of the same chemists.
When these compounds are acted upon by potassium or sodium, the results are fluates of potash or soda, with silicum, hydrogen, or boron, according to the compound operated upon.
With regard to these results, there are three hypotheses which may be maintained. One is, that fluoric acid consists of an inflammable base united to oxygen. A second, that it consists of a simple base, which may he called fluorine (analogous to chlorine), united with hydrogen. A third is, according to the tets of the phlogistians, that fluoric acid, like metallic oxides, is liable to combine with hydrogen, and form an inflammable compound. Since all the phenomena may be explained according to any one or other of these hypotheses, the sole question is, which of these explanations is best, as being most conformable to the general series of chemical facts with which we are at present acquainted.
