OF ALLOXANIC ACID. 1<) 



Carbon, 31-06 or 8 atoms 6 or per cent. 32-21 

 Hydrogen, 3.57 or 5 atoms = 0-625 . 3-35 

 Azote, 36-24 or 4 atoms = 7-0 . 37.59 



Oxygen, 29-13 or 5 atoms = 5-0 . 26-85 



100-00 18-625 100- 



The difference between the experimental and calculated re- 

 sults in this case are rather too great. This difference Wohler 

 and Liebig ascribe to the presence of a little uramile* in the salt, 

 which is a product of the decomposition of alloxantin by am- 

 monia. 



It is easy to explain the formation of mycomelic acid. One 

 atom of alloxane and two of ammonia are decomposed into one 

 atom of mycomelic acid and five atoms of water. 



1 atom alloxane, C 8 H 6 Az 2 O 10 "J /"I atom mycomelic 



2 atoms ammo- i i ac ^' ~ C 8 H 5 Az 4 O 5 

 nia, H 6 Az 2 ) V 5 atoms water, H 5 s 



C 8 H 10 Az 4 10 C 8 H 10 Az 4 10 



Dry mycomelic acid possesses exactly the same composition 

 as allantoin when united to oxide of silver. 



Wohler and Liebig attempted to determine the atomic weight 

 of this acid by analyzing mycomelate of silver, but they did not 

 consider the results which they obtained as deserving of confi- 

 dence ; because the yellow gelatinous precipitate obtained by 

 mixing nitrate of silver with mycomelate of ammonia changes 

 its colour even when washed in the dark, It becomes brown, and 

 when dried on the water-bath assumes the form of a hard green 

 mass, giving an olive coloured powder, not completely soluble in 

 ammonia. They obtained from this salt by combustion 44.39 

 per cent of silver, equivalent to 47*68 of oxide of silver. This 

 would make the salt, 



Mycomelic acid, 52-32 or 15-91 



Oxide of silver, 47-68 or 14-5 = 1 atom. 



100- 



According 'to this analysis the atomic weight of mycomelic acid 

 is 15-91. The difference between this weight and that of the 

 liydrous acid is 2*715, which is more than two atoms of water, 



* This substance will be described in a subsequent chapter of this work, 



D 



