188 Ohervations on some Points [March, 



very skilful chemist, that his results furnish very near approxima- 

 tions to the truth ; but from the extreme difficulty attending such 

 analyses, I do not conceive that perfect precision can be attained at 

 first ; but 1 think that the atomic theory furniihes us with such 

 additional checks that, by a judicious application of them to the 

 constitution of these acids as determined by Berzelius, we may 

 obtain results approaching exceedingly near the truth. I shall at 

 present apply that theory to the investigation of the composition of 

 oxalic acid. 



According to Berzelius, that acid is composed as follows : — 



Oxygen 6^*534 6 atoms 



Carbon 3:V222 4 



Hydrogen 0-244 1 



100-000 11 



But as 1 consider the weight of an atom of hydrogen as twice as 

 great as Berzelius makes it, we must, in order to represent the 

 composition of this acid according to my numbers, double the 

 number of atoms of oxygen and carbon which it contains. It will 

 then be composed of 



Oxygen 12 atoms 



Carbon 8 



Hydrogen 1 



21 



So that It is a very complicated body. The weight of an inte- 

 grant particle of it must be 18 140. We might, indeed, reduce 

 the number of atoms in this acid to 1 1 by doubling the quantity of 

 hydrogen, obtained by Berzelius ; for the difference seems to be 

 within the limits of the unavoidable errors to which such experi- 

 ments are liable. But Berzelius does not think that he could have 

 committed any such error. Let us, therefore, have recourse to 

 another method of determining the weight of an integrant particle 

 of oxalic acid. 



From the analysis of oxalate of lead made with great care by 

 Berzelius it appears to be a compound of 



Oxalic acid 100 



Yellow oxide of lead 307-5 



Now there can be no doubt, from a comparison of all the genera 

 of salts hitherto examined, that oxalate of lead is a compound of 

 two integrant particles of oxalic acid and one integrant particle of 

 yellow oxide of lead ; so that to find the weight of an integrant 



particle of oxalic acid we have this proportion :— 307-5 : — :: 



27-974 -. 4-5 IB = an integrant particle of oxalic acid. Now this is 

 just the fourth part of the weight of that acid resulting from the 



