46 ANIMAL ACIDS CONTAINING AZOTE. 



ance. Alloxanate of ammonia precipitates the salts of silver 

 white. The free acid dissolves zinc with the disengagement of 

 hydrogen gas. Sulphuretted hydrogen has no action on it. 



Alloxanate of silver was analysed in Liebig's laboratory. It 

 was formed by mixing together solutions of alloxane, ammo- 

 nia, and nitrate of silver. It became gray when dried, and was 

 found composed of, 



Alloxanic acid, . 38-53 or 18-17 



Oxide of silver, . 61-47 or 29 = 2 atoms. 



100- 



The atomic weight by this analysis is 18-17. 



When the salt was decomposed by oxide of copper, the azotic 

 gas and carbonic acid gas evolved were to each other as 1 : 4. 

 The mean of two analyses in Liebig's laboratory gave, 

 Carbon, . 12-91 or 8 atoms 6-0 or per cent. 12-84 



Hydrogen, . 0-68 or 2 atoms 0-25 . 0.54 



Azote, . 7-53 or 2 atoms = 3-5 . 7-48 



Oxygen, . 17-41 or 8 atoms = 8-0 . 17-11 



Oxide of silver, 61-47 or 2 atoms = 29.0 . 62.03 



100-00 46-75 100.00 



This makes the constitution of the acid C 8 H 2 Az 2 O 8 = 17-75. 

 Doubtless the crystallized acid contained two atoms of water, 

 which were replaced in the salt by two atoms of oxide of silver. 

 Hence the constituents of the crystals must have been C 8 H 4 

 Az 2 O 10 = 20. 



Alloxanate of silver deflagrates at a temperature much be- 

 low redness. The residue gives out a considerable quantity of 

 cyanic acid. 



Alloxanate of Barytes. This salt, prepared in the way de- 

 scribed in the beginning of this section, constitutes short trans- 

 parent prisms or a precipitate in brilliant crystalline plates. It 

 loses water when heated to 212. The crystals then become 

 opaque and milky-white. When decomposed by oxide of copper 

 the volumes of azotic and carbonic acid gases evolved are to each 

 other as 1 : 3. When heated to 248 it loses 20 per cent of water. 



100 parts of the salt were found to contain 49-35 of barytes. 

 This was the mean of two analyses, the first yielding 49*25, the 

 second, 49-46 per cent. 



