288 



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, ba- 

 rytes 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 3 9 '5, which represents the particle of oxalic acid. Re- 

 verting 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 con- 

 sist 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 esti- 

 mation 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 parts of acid to 

 yield, 



Carbonic acid 55'70, instead of 59'53, actually obtained. 



Inflammable gas . . 28*64, 24'28, 



Water 11-81, 11-51, 



Charcoal 3-80, 4-68, 



It is impossible, Dr. Thomson observes, to expect exact corre- 

 spondence till the numbers representing the weights of the elemen- 

 tary atoms be ascertained with accuracy, instead of the round num- 

 bers which he has assumed, for the purpose of showing an approxi- 

 mation of the theoretic inferences to the results obtained by experi- 

 ment. 



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 hydro- 

 gen, and 24 carbon, as the true elements, if these numbers be re- 

 spectively divided by the weights of their single particles, the num- 

 ber of atoms of each which combine to form sugar are to each other 

 as 5, 3, and 4 respectively. 



