46 Mr. Simpson-— ^czWs /rom the Cyanides of [Dec. 10, 



organic acid combined with the potash. The free acid was then separated 

 from the nitrate of potash by means of alcohol. 



. On evaporating the alcohol a dark-coloured residue was obtained, which 

 was dissolved in hot water and treated with chlorhie. Finally a silver-salt 

 of the acid was prepared by the following kind of fractional precipitation : — 

 About one-third of the neutralized acid was first precipitated by the 

 cautious addition of a solution of nitrate of silver. The liquor was then 

 filtered, and the remainder of the acid was converted into the silver-salt. 

 By these means I obtained, instead of a brown, a perfectly white precipitate, 

 which yielded an acid in colourless crystals when decomposed by sulphu- 

 retted hydrogen. Dried at 100° Cent, these crystals gave on analysis 

 numbers which agree tolerably well with the formula C^^ H3 O^q, as will be 

 seen from the following Table : — 



Experiment. 





Theory. 





.. 40\54 



H, .. 



5-40 



0„ .. 



.. 54-06 





100-00 



I. II. 



41-62 41-61 

 5-17 5-16 



These analyses were performed on specimens prepared at different times. 

 This acid is soluble in water, alcohol, and ether. It has a pure acid taste. 

 It melts at about 135° Cent., and at a higher temperature suffers decompo- 

 sition. The free acid gives an abundant white precipitate with acetate of 

 lead, soluble in strong acetic acid. It is not precipitated by lime-water. 

 The neutrahzed acid yields a bulky white precipitate with corrosive subli- 

 mate, and a pale brown with perchloride of iron. Copper salts give a 

 bluish-white precipitate. Chloride of barium is not affected. The forma- 

 tion of this acid may be explained by the following equation : — 



C, H, O, Cy, + 2 (^1 } 0,)+4H0=C„|= } 0,„+2NH3. 



I have also analyzed the silver-salt of this acid. As it sufi'ers decompo- 

 sition at the temperature of boiling water, I was obliged to effect its 

 desiccation by placing it in vacuo over sulphuric acid. It is slightly soluble in 

 water. The numbers it jdelded on analysis agree verj- well with the formula 



Theory. Experiment. 



C ?^ 



I. II. 



.... 16-61 



Hg 1-65 1-39 



.... 22-17 



Ag2 .... 59-61 60-67 



100-00 



