Page:Proceedings of the Royal Society of London Vol 1.djvu/461

Rh exprew the relation of this body to hydrogen, the unit of the scale. For since in sulphuretted hydrogen the hydrogen is not altered in bulk by the sulphur it holds in solution. the increase of weight shows the proportion of sulphur combined. And so likewise in sulphurous acid gas, the bulk is not greater than that of the oxygen which it contains; and since the speciﬁc gravity is double that of oxygen, the increase proves that sulphur, in this instance, has combined With an equal weight of oxygen. When sulphur combines with a larger pro- portion of oxygen, the presence of Water appears to be requisite as the medium of union. In the phosphoric acid, on the contrary, water is not necessary for uniting the full proportion of oxygen with which phosphorus is capable of combining.

With respect to the water that has been observed to be retained by many earths, and metallic precipitates, it is remarked, that this is probably combined with them in deﬁnite proportion, and that the presence of the water has considerable inﬂuence on their colours, and on other properties.

The present account is intended as a caution to others against the dangerous effects of the very explosive detonation, by which the author has himself been a sufferer. His attention was ﬁrst directed to the subject by a letter received from France, mentioning that about twelve months since, a compound had been discovered of azote with chlorine, which appears in the form of an oil heavier than water, and which explodes, by a gentle heat, with all the violence of the fulminating metals. The letter adds, that this discovery cost the operator an eye and a ﬁnger. Since the letter contained no account of the mode of preparing the compound, and as none could be found in any of the French journals, Sir Humphry Davy pursued a hint given him by Mr. Children, who informed him that his friend Mr. Burton had, in the month of July last, observed the formation of a volatile oily substance in a solution of nitrate of ammonia. exposed to chlorine in the state of gas. In repeating the experiment, the author perceived ﬁrst an oily ﬁlm on the surface of the ﬂuid, which gradually collected into small globules, and fell to the bottom. One of these globules being taken out while ﬂoating on the surface of the water, and slightly warmed, exploded with brilliant light, but with— out any violence of detonation. .

In a series of experiments carried on jointly with Mr. Children and Mr. Warburton, other ammoniacal solutions were substituted, and it was found that the same product was obtained by means of oxalate of ammonia, or by a weak solution of pure ammonia. The ﬁrst instance that occurred of violent explosion, was in their endeavours to form larger quantities in a Wolfe’s apparatus, by a series of bottles containing the different solutions.