1>8 On the Definite Proportions in which the [Fbb. 



keep the whole tube red hot during the combustion of tlie oxalate. 

 Another portion of the oxide was changed into suhrauriate, as I 

 satisfied myself by digesting the oxide in nhric acid, after it had 

 been well washed. Oxymiiriatic acid was disengaged, while at the 

 same time neutral nitrate and muriate of lead were 'formed. 



Though in consequence of this eircupistance, it is impossible to 

 determine the quantity of carbon with perfect precision, we know 

 at least that it must contain more tlian 32*6, which would have 

 been the result if all the oxide had been converted into minium, 

 and less than o5 per cent., which would have been the result if wo 

 part of the oxide hud been converted into .minium. By attending 

 to these two extremes, we find witiiout difficulty, that the oxygen 

 and carbon exist in such proportioris in oxalic acid, that there is 

 one volume of caPbon for every 1-i volume of oxygen, or two 

 volumes of carbon for every three volumes of oxygen. 



To determine the composition of oxalic acid, we must then 

 ascertain the relation between tlie volumes of its oxygen and 

 hydrogen. This is difficult, because the quJintily of hydrogen is so 

 gmall, that analysis is not able to decide concerning it. I think, 

 however, that we can find it from other cMcumstances. There can 

 be no doubt that the composition of oxalic acid is such, that in the 

 oxalates the hydrogen of the acid is combined with a certain num- 

 ber of entire volumes of the radicle of the base ; but saline bases 

 jnay contain one, two, or three volumes of oxygen, without this 

 producing any change in the ratio of the oxygen of the acid with 

 tb.at in the base. \Mien we reflect on this, we perceive that with 

 the known ratio between the carbon and oxygen in oxalic acid, 

 there are only three modes of combination in which the above 

 stated circumstance, (that a volume of hydrogen in the acid is 

 combined with a certain number of entire volumes of the radicle 

 iof the base,) can take place; namely, H + 2 C + 3 O, or H + 

 12 C + ISO, or H + 24 C + 3C O. For the degrees above this 

 are not probable. The difFeronce between these three degrees is 

 so great, that the quantity of hydrogen found by experiment must 

 be sufficiently exact to determine which of them belongs to oxalic 

 acid. But analysis has given much more hydrogen thun is consist- 

 ent with the third of these, but less than would be requisite for the 

 first mode of combination. But all the circumstances of the ana- 

 lysis agree perfectly with the idea, that oxalic acid is composed of 

 one volume hydrogen, 12 volumes'carbon, and 18 volijiuies oxygen.* « 

 This constitutes per cent. : 



* In my memoir On the cause of Cl?eniical Proportions, jinnnU of Philusoph)/, 

 ■December, lt)]3, 1 have stated by a ini.-tslke in the calriilntion that this acid con- 

 tains 27 volumes of carbon. It is obviouK that this error is of no consec|i)eiic« 

 relative to (he subject treated of in liiat memoir. 1 acicnowlcdge however liiut 

 kt present I do not lay much stress on fliat argument against the corpuscular doc- 

 trine. For it is clear that the compound atoms of organic nature ought to have a 

 ^ochanic;al btructureus diiTercut from tUut of inorgauic atoms as tU«ir compoiiitio* 

 h <iii'«reot. 



