Chemical Constitution of Metacetonic Acid. 269 



the solution becomes blackened on boiling. The crystals dried 

 over sulphuric acid in vacuo had the composition of meta- 

 cetonate of silver. 



I. 0*211 grm. gave, vjrhen burnt vi'ith oxide of copper, 

 0-153 grm. carbonic acid and 0-055 grm. water. 



II. 0'167 grra. gave on careful ignition 0-100 grm. of me- 

 tallic silver. 



100-00 15 100-00 



The salt of barytes is very soluble in water ; the solution of 

 the salt evaporated to dryness and dried for a long time at 

 212°, gave the following numbers : — 



I. 0-339 grm. gave 0-311 grm. carbonic acid and 0-116 

 grm. water. 



II. 0-258 grm. gave 0-211 grm. sulphate of baryta. 



Theory. 

 Carbon . . . 24-98 

 Hydrogen . . 3-79 

 Oxygen . . . 17*58 

 Barytes . . . 53 65 



100-00 100-00 



The lead compound has the sweet taste of acetate of lead : 

 it does not appear to crystallize, but dries up to a tough 

 amorphous saline mass. A portion dried at 212° and in vacuo 

 gave exactly the quantity of oxide of lead, corresponding to 

 the formula PbO, Cg Hg O3, namely, — 



0*446 grm. gave 0-282 grm, oxide of lead and 0*021 grm. 

 metallic lead, equivalent to 63*40 per cent, instead of 63*19. 



From the above analyses, there can be no doubt that the 

 acid product of the action of caustic potash upon cyanide of 

 ethyle is metacetonic acid. The same result is produced by 

 weak sulphuric acid (1 part acid to 2 parts water). The silver 

 salt prepared from the acid product of distillation in this case 

 exhibited the properties described above, and an estimation 

 of the oxide of silver gave the follow-ing result : — 



I. 0*150 grm. when ignited gave 0*090 grm. metallic silver, 

 corresponding to 64*30 per cent, oxide of silver ; the theo- 

 retical proportion being 64*07 per cent. 



The mode of decomposition of cyanide of ethyle described 

 is therefore quite analogous to that of benzoe-nitrile and 

 valero-nitrile ; and if metacetonic acid is considered as ethyl- 



