364 Qn the Products of the Oxidation of Wool, 



with bicarbonate of potash : and we made the observation that 

 the acid requires exactly the theoretical quantity of "bicarbo- 

 nate of potash in order to neutralize it. 



The resulting solution of potash-salt was evaporated to dry- 

 ness in the water-bath, and formed a straw-coloured transpa- 

 rent solid. It contained 21*68 per cent, of potassium. The 

 formula (C 4 H 4 E"K0 2 ) 2 5H 2 requires 21*47 per cent, of 

 potassium. When the salt is deposited from strong alcohol it 

 dries up, at 100° C, to a solid containing rather less water, 

 its composition being (C 4 H 4 N K0 2 ) 2 4 H 2 0. Above the tem- 

 perature of the water-bath and at temperatures below 140° C. 

 there is a very gradual loss of water ; and by prolonged and 

 repeated heating to 190° C. half of the water is driven off, and 

 the salt is found to have the formula 



C 4 H 4 NK0 2 ,H 2 0, 



which requires K per cent. 25 '21. Experiment gave K per 

 cent. 25*8. 



At temperatures higher than 190° C. decomposition began 

 to take place, ammonia and a smell of organic cyanides being 

 disengaged. The potash-salt undergoes decomposition before 

 it parts with the last atom of water of hydration. 



As has already been indicated, the potash-salt is exceedingly 

 soluble in water. It is also very soluble in 40-per-cent. alcohol; 

 but in strong alcohol (84-per-cent. alcohol for instance) its 

 solubility is very slight. 



When the potash-salt is heated for some time to temperatures 

 between 200° and 220° C, with about one and a half times 

 its weight of caustic potash, it undergoes decomposition appa- 

 rently quite completely, and ethylamine is given off. On 

 examination of the solid mass after the reaction was over 

 we found that it contained abundance of oxalate of potash ; 

 but we found only minute traces of volatile organic acids. 

 We proved also that the cyano-propionic acid had undergone 

 complete decomposition. We looked carefully for succinic 

 acid; and if present at all, it was not present in appreciable 

 quantity. 



The reaction is 



C 4 H 5 N0 2 + 2KHO = C 2 3 K 2 + NC 2 H 7 ; 



and accordingly the acid is isocyano-propionic acid. 



Cyano-propionate of Lime. — We prepared this salt by heat- 

 ing an aqueous solution of the acid with excess of finely divided 

 carbonate of lime, filtering to remove the excess of carbonate 

 of lime, and evaporating the solution of the lime-salt in the 

 water-bath. The salt, after being dried at 100° C. for some 



