Page:Proceedings of the Royal Society of London Vol 1.djvu/308

Rh to atom; but that they may also combine in the proportion of two or more particles of one sort with one of another.

Dr. Thomson observes, that the same law holds also with respect to salts, and that numbers may be affixed to each of the acids and to each of the bases; which numbers, or their multiples, will represent them in all the combinations into which these bodies enter.

In this scale the particle of sulphuric acid is represented by 33, muriatic acid by 18, nitric acid by 17, carbonic acid by 17.5, barytes 67, lime 23, soda 24, ammonia 6.

From these data, and from the proportion in which oxalic acid has been found above to combine with several bases, Dr. Thomson assigns the number 39.5, which represents the particle of oxalic acid. Reverting next to the proportion of its elements, and to the weights of their respective atoms, he ﬁnds the integrant particle of oxalic acid to consist of 4 atoms of oxygen, 3 of carbon, and 2 of hydrogen; the aggregate weights of which amount to the same number, 39.5, at which he had arrived by a different mode of estimation.

According to these proportions, 100 parts of oxalic acid will consist of its three elements, in the proportion of 61, 34 and 5, instead of 64, 32 and 4; numbers not exactly corresponding, but, in the estimation of Dr. Thomson, approaching sufficiently near to heighten the probability of the reasoning employed.

We may next conceive 3 particles of oxalic acid thus constituted to be decomposed at once, and to yield 4 particles of carbonic acid, 2 of carburetted hydrogen, and 2 of carbonic oxide, 3 of water, and 1 particle of charcoal; and might thence expect 100 pans of acid to yield,

It is impossible, Dr. Thomson observes, to expect exact correspondence till the numbers representing the weights of the elementary atoms be ascertained with accuracy, instead of the round numbers which he has assumed, for the purpose of showing an approximation of the theoretic inferences to the results obtained by experiment.

In an analysis of sugar, which follows, by a series of experiments and of hypothetical reasoning, different from the experiments and reasoning of Lavoisier, Dr. Thomson nevertheless agrees with him, to great accuracy, in his results: and assuming 64 oxygen, 8 hydrogen, and 24 carbon, as the true elements, if these numbers be respectively divided by the weights of their single particles, the number of atoms of each which combine to form sugar are to each other as 5, 3, and 4 respectively.