URIC ACID. 155 



This difference is reducible to an atom of water 

 and two atoms of carbon. The sulphuric acid 

 seems to remove the atom of water, which de- 

 stroys the equilibrium of the constituents of the 

 acid. The two surplus atoms of carbon are con- 

 verted into carbonic acid, by uniting with the 

 oxygen of the tritoxide of manganese. 



If we suppose all the substances employed in 

 this experiment pure, it is evident that the ato- 

 mic quantities requisite for the decomposition of 

 the tartaric acid, and formation of formic acid, 

 must be 



1 atom tartaric acid . . 9*375 



2 atoms tritoxide of manganese 1 1 



2 atoms sulphuric acid . 12*25 



Or, 24*75 of bitartrate of potash might be sub- 

 stituted with equal advantage, instead of the 

 9*375 of tartaric acid. 



SECT. IX. 



OF THE ATOMIC WEIGHT OF URIC ACID. 



THIS acid was detected by Scheele, and some of 

 its most characteristic properties determined. It 

 was afterwards examined more in detail by Dr. 

 Henry of Manchester, who made it the subject 



