ALLANTOIX. 109 



bases into salts, and therefore is not entitled to be considered as 

 an acid. The oxide of silver makes the only exception to this. 

 Allan toin forms with it a compound, which is a white powder. 

 It may be obtained by mixing aqueous solutions of nitrate of sil- 

 ver and allantoin together, and adding ammonia drop by drop as 

 long as a precipitate continues to fall. The dilute acids decom- 

 pose this compound, disengaging the allantoin. 



At a high temperature it is decomposed by the caustic alka- 

 lies into ammonia and oxalic acid. This decomposition is most 

 easily observed when we employ barytes. If we dissolve allan- 

 toin in boiling hot barytes water, ammonia is disengaged and a 

 white powder falls, which is oxalate of barytes. When allantoin 

 is heated with sulphuric acid exactly the same decomposition 

 takes place ; only instead of oxalic acid, carbonic acid and car- 

 bonic oxide are disengaged, and the ammonia combines with the 

 acid. 



Allantoin being subjected to an ultimate analysis in Liebig's 

 laboratory, was found composed of, 



Carbon, . 30-20 or 4 atoms = 3-000 or per cent. 30-38 

 Hydrogen, 4-04 or 3 atoms = 0-375 ... 3-80 



Azote, . 35-27 or 2 atoms 3-500 ... 35-44 

 Oxygen, . 30-49 or 3 atoms = 3-000 ... 30-38 



100-00 9-875 100- 



We might consider it as a compound of, 



2 atoms cyanogen, . C 4 Az 2 



3 atoms water, . . H 3 O 3 



To convert it into oxalate of ammonia, or C 2 O 3 +Az H 3 , we 

 must add three atoms water. We have then, 



Allantoin, . C 4 H 3 Az 2 O 3 



3 atoms water, . H 3 O 2 -^ i~ 3 



C 4 H 6 Az 2 O 6 . Now two atoms 

 oxalate of ammonia, C 4 O 6 + Az 2 H 6 



The compound of allantoin and oxide of silver being analyzed 

 in Liebig's laboratory, was found composed of, 

 Allantoin, . 56-45 or 18-79 

 Oxide of silver, 43-55 or 44-5 



100- 



