Page:Proceedings of the Royal Society of London Vol 1.djvu/502

Rh So also silicated ﬂuate of ammonia, or ﬂuohorate of ammonia, when acted upon by chlorine, yield no silica, or boracic acid, unless in consequence of the presence of moisture; but they. form muriate of ammonia, and either silicated ﬂuoric or ﬂuoboric gas.

When charcoal was ignited in either of these gases no decomposition was effected, but only a disengagement of a little inﬂammable gas from the charcoal. Neither was liquid ﬂuoric acid decomposed by charcoal heated to whiteness in a tube of platina.

According to the author's experiments on the decomposition of ﬂuor spar by sulphuric acid, the sulphate of lime which remains after complete decomposition weighs more than the spa: decomposed in the proportion of 175 to 100. But in order to obtain this result, it is necessary to collect the very purest white Derbyshire ﬂuor, and to distil repeatedly to dryness, after the addition of fresh acid at each repetition. By computing upon the eighth result, and supposing the number representing calcium to be 40, that for ﬂuorine is estimated to be 34-2.

By forming ﬂuate of potash from a known quantity of subcarbonate. the number obtained for ﬂuorine appeared to be about 32'6.

From these experiments, and others made on the quantity of ﬂuate of potash obtained from hydrate of potash, the author infers that the number representing ﬂuorine may be estimated at about 33.

Two cubical inches of ammoniacal gas, weighing 36 grains, were found to combine with one of silicated ﬂuoric gas, 'which were found to weigh 1107, the number for which is thence inferred to be 98'4; and it is presumed to consist of two parts ﬂuorine, and one of silicious basis.

The author has made many experiments with the hope of deter- mining the quantity of oxygen in silica, but has not succeeded tollis satisfaction. However, since one part of silica requires more than three times its weight of potassium to decompose it, this seems to Show that silica cannot contain much less than half its weight of oxygen. But he has not been able to obtain its basis in a separate state so as to ascertain its exact nature.

Sir Humphry Davy has at various times made many experiments to endeavour to detect oxygen in chlorine, in conformity to the opinion still maintained by many persons, that this is one of its elements, but without success. Sulphuret of lead when acted upon by chlorine, gave the muriates of sulphur and of lead, and not sulphate of lead, as might possibly be expected. Neither is muriate of lead decomposed by sulphureous acid gas, which might be expected to take oxygen if any were present.

It appears, on the whole, to the author impossible to give stronger evidence of chlorine being undecompounded. In his estimation it ranks with gold, silver, hydrogen, or oxygen. He admits that persons may doubt whether these are elements, but thinks it not philosophical to doubt whether it has yet been decompounded.

In reply to some arguments lately advanced by Professor Berzelius in favour of the presence of oxygen in chlorine, deduced from the