Page:Proceedings of the Royal Society of London Vol 1.djvu/34

Rh and showed marks of putrescence, the light seemed to be more quickly extinguished. In some instances the light was ejected in globules, like quicksilver when rubbed with any unctuous substance, and afterwards adhered to the sides of the vessel in the form of a lucid ring. The serum both of healthy and diseased persons retained the luminous appearance somewhat longer than the crassamentum and frequently recovered it when agitated. Urine, both fresh and stale, and bile, showed little disposition to retain this light. Lastly, milk and cream, illuminated by mackerel light, acquired great brighness, and retained it for upwards of twenty-four hours; but when either of these turned sour, they contracted a very extinguishing property, the light in some case vanishing almost instantaneously.

Account of a Series of Experiments, undertaken with the view of decomposing the Muriatic Acid. By Mr. William Henry. Communicated by the Right Hon. Sir Joseph Banks, Bart. P.R.S. Read Feb. 27, 1800. [Phil. Trans. 1800, p. 188.]

In the introduction to this paper the author points out the great utility that would accrue to chemical science, were it possible to arrive at a complete analysis of certain acids, since the new, and indeed every system of chemistry, will ever be incomplete and liable to subversion till the particular agents here alluded to have been resolved into their constituent principles. The obstacles, however, which impede the progress of this investigation, are much greater than may appear at ﬁrst sight; and among these are particularly mentioned the difficulty of obtaining the acids completely separated from all other substances, which, by their presence, will ever tend to introduce uncertainty into the results of the process; it being observed that the attraction between compound particles at all times increases in proportion as we recede from the point of saturation, and that the smallest remnant is often sufficient to perplex all further analysis. The liquid state is thought to be totally unﬁt for the purpose of this inquiry: and after some other structures, it is shown that the state of the gas is the only one in which acids can become proper objects of analytical investigation.

In the series of his experiments on the muriatic acid in the gaseous state, Mr. Henry employed the electric ﬂuid as an agent much preferable to artiﬁcial heat. “This mode of operating," he says, “enables us to conﬁne accurately the gases submitted to experiment; the phaenomena that occur during the process may be distinctly observed, and the comparison of the products with the original gases may be instituted with great exactness.” The action of the electric ﬂuid itself, as a decomponent, is no doubt extremely powerful; since it is capable of separating from each other the constituent parts of water, of the nitric and sulphuric acids, of the vegetable alkali, of nitrous gas, and of several other bodies whose components are known to be strongly united. The experiments were