PYRURIC ACID. 39 



tion is evaporated to dryness we obtain the pyruric acid unal 

 tered. 



Lime forms with pyruric acid a salt which crystallizes irregu- 

 larly, and which has a bitter and slightly acrid taste. When ex- 

 posed to a gentle heat this salt melts, and on cooling assumes the 

 appearance of yellow wax. When calcined in a platinum crucible 

 it left 8 -6 of lime. Hence Chevallier and Lassaigne concluded 

 that it was a compound of 



Pyruric acid, . 9 1 -4 or 3 7 * 1 

 Lime, . . 8-6 or 3-5 



100-0 



When barytes is united to this acid a white pulverulent salt is 

 obtained little soluble in cold water. With potash and ammonia 

 it forms soluble and crystallizable salts. The pyrurate of soda 

 is soluble, but it does not crystallize. The acids when dropt into 

 a solution of these salts precipitate the pyruric acid in the form 

 of a wh ite powder. Of all the metallic salts tried, only the salts of 

 peroxide of iron, black oxide of copper, oxide of silver, oxide of 

 mercury, and the trisacetate of lead are precipitated by the py- 

 rurate of potash. 



The pyrurate of peroxide of iron has a chamois-leather colour, 

 that of copper is light-blue, and those of silver, mercury, and lead 

 white. The salt of lead formed by mixing solutions of pyrurate 

 of soda and trisacetate of lead is composed, according to Che- 

 vallier and Lassaigne, of 



Pyruric acid, . 28-5 or 16*6 



Oxide of lead, . 71-5 or 48 or 3 atoms. 



100O 



If we suppose the pyrurate of lime analyzed to be a bisalt and 

 this a tris-salt, the atomic weight of pyruric acid will be 17*5. It 

 was analyzed by Chevallier and Lassaigne, who obtained 

 Carbon, . . 28-29 

 Hydrogen, . . 10-00 

 Azote, . . 16*84 



Oxygen, . . 44-32 



99-45 



There is no likelihood that these numbers are exact. The 

 smallest number of atoms that would agree with this analysis is, 



