Decompositio7i of Pyromeconic Acid, 163 



posed to a temperatm-e of 212°, it loses no weight ; but heated 

 to a higher temperature, it burns with a slight deflagration 

 without pre\'ious fusion. The following are the results of ana- 

 lysis after the salt had been thoroughly washed with alcohol, 

 and dried at 212°. The other salts of this acid were also dried 

 at 212° previous to analysis. 



4-81 grains substance gave 5-55 carbonic acid and 1 -06 water. 

 4-33 gi-ains substance gave 2-24 carbonate of bai-yta. 



100-00 100-00 188-55 



The composition of the salt is therefore represented by the 

 formula BaO, C '« H^ 0^ + HO. 



Pyromeconate of Strontia. — When alcoholic solutions of ni- 

 trate of strontia and pyi-omeconic acid, made ammoniacal, are 

 mixed, there immediately ensues a precipitate of minute silky 

 needles, which by solution in water are obtained in stellar groups 

 of a yellowish colom-. As precipitated, it is colourless, sparingly 

 soluble in cold water and alcohol, more so in hot, and reacts 

 strongly alkaUne. 224 grains aqueous solution at 68° gave 3-00 

 grains on evaporation at 212° =1*3 per cent. It loses nothing 

 at 212°, and at a higher temperature is infusible, but burns with 

 a shght explosion. 



The well-washed substance gave the following results on ana- 

 lysis, the strontia being determined as carbonate. 



5-875 gi-ains substance gave 7-79 carbonic acid and 1-35 water. 

 7-97 grains substance gave 3-58 carbonate of strontia. 



100-00 100-00 163-78 



The formula of the salt is therefore SrO, C^o H^ O^-f- HO. 



Pyromeconate of Lime. — This salt is obtained in the form of 

 small colourless silky needles when a warm ammoniacal solution 

 of pyromeconic acid is added to acetate of lime in excess. It is 

 slightly soluble in boiling alcohol, but rather more so in water, 

 from which it deposits itself by gradual cooling of the solution 

 M2 



