1819.] Acids, Alkalies, and their Compounds. 289 



to be assumed as cannot be supposed. The other conclusion, 

 therefore, follows : it is rendered more probable by other consi 

 derations, which give force to the opinion that hydrogen and 

 carbon enter into more numerous proportions than have been 

 assigned ; and it is nearly established by the results of this case 

 itself. Supercarburetted hydrogen is composed of 100 of 

 carbon with 17-5 of hydrogen; carburetted hydrogen of 100 with 

 35. In oxalic acid, 26*5 of carbon are combined, according to 

 the analysis of Berzelius, Avith 2*5 of hydrogen, which is in the 

 proportion of 100 to 9*4. Now this deviates little, and not more 

 than what may fairly be referred to inaccuracy in the estimation 

 of the proportions in one or other of the compounds, from the 

 fourth of the highest proportion, that in carburetted hydrogen;* 

 and hence, in conformity to the law usually observed, hydrogen 

 probably combines with carbon in proportions following the ratio 

 of 1, 2, 3, 4 ; and taking a mean which further investigation 

 may determine with precision, 100 of carbon may be supposed 

 to combine with 9, 18, 27, and 36, of hydrogen. The proportion 

 in oxalic acid will be conformable to the first of these relations, 

 or half that in supercarburetted hydrogen. 



Tartaric acid, which is next in strength to the oxalic, or is 

 even equal or superior to it in acidity, appears to be the same 

 combination with a larger proportion of hydrogen. 



Gay-Lussac employed tartrate of lime as the medium to 

 decompose the acid. In this state, while the water of crystal- 

 lization of the acid is excluded, its composition is not subverted, 

 for there is in the formation of tartrate of lime no abstraction of 

 what is called combined water. The results, therefore, give the 

 real constitution of the acid. The proportions he assigned are 

 carbon 24*05, oxygen 69*3, hydrogen 6*62. Berzelius operated 

 on tartrate of lead. The proportions he assigns are carbon 

 35-98, oxygen 60*21, hydrogen 3*807. But in the formation of 

 tartrate of lead by the action of the oxide on the acid, a large 

 quantity of water is formed. This being taken into calculation, 

 his results agree perfectly with those of Gay-Lussac. 



The proportion of the carbon to the oxygen, it is evident, is 

 not much different from that which constitutes carbonic acid ; 

 and the deviation is not greater than may fairly come within the 

 allowance due to errors, liable to be present in a subject of 

 analysis so difficult. 



The proportion of hydrogen is much larger than that in oxalic 

 acid : it must, however, in conformity to the law which has been 

 stated as regulating the proportions in ternary acids, bear a 

 certain relation to the radical of the acid, that is, to the carbon. 

 And it is interesting to discover that this larger quantity is 

 precisely the other definite proportion which it has appeared 



* The composition of either of the carburetted hydrogen gases is not so well 

 determined as to exclude a correction sufficient to establish a perfect coincidence. 



Vol. XIV. N° IV. T 



