110 ANIMAL OXIDES WITH AZOTE NOT OILY. 



If it consist of 2 atoms allantoin united with one atom oxide of 

 silver, then an atom of allantoin will weigh 9 '4, which approaches 

 the number 9*875, resulting from Liebig's formula. 



The constitution of allantoin, urea, and oxalic acid being 

 known, it is easy to see what happens when uric acid and per- 

 oxide of lead are made to act upon each other. 



1 atom uric acid is, . C 10 Az 4 H 4 O 6 

 Subtract 1 atom urea, C 2 Az 2 H 4 O 2 



Remains, . . C 8 Az 2 O 4 



Add O 2 from peroxide of lead, O 2 



C 8 Az 2 O 6 

 Now C 8 Az 2 O 6 are resolvable 



into 2 atoms oxalic acid, C 4 O 6 



2 atoms cyanogen, . C 4 Az 2 



C 8 Az 2 O 6 

 Now we have seen already that if three atoms water be added 



to 2 atoms cyanogen, we have an atom of allantoin or C 4 Az 2 



H 3 3 . 



Thus we see that 1 atom of uric acid -f- 2 atoms oxygen -f 



3 atoms water, form 



1 atom urea, . C 2 H 4 Az 2 O 2 



2 atoms oxalic acid, . C 4 O 6 

 1 atom allantoin, . C 4 H 3 Az 2 O* 



C 10 H 7 Az 4 n 



Which is the same as 



1 atom uric acid, a C 10 H 4 Az 4 O 6 



2 atoms oxygen, i-~ O 2 

 2 atoms water, . H 3 O 3 



C 10 H 7 Az 4 O 11 



The carbonic acid evolved is obviously owing to the action of 

 the peroxide of lead on the oxalic acid. 



Liebig conceives that the reason why the atomic weight of al- 

 lantoin in the allantoate of silver is less than that deduced from 

 analysis, is that two atoms of allantoin, when they unite with 

 oxide of silver, lose an atom of water, so that they become C 8 

 Az 4 H 5 O 5 . 



