Products of the Oxidation of Wool. 357 



times its weight of caustic potash, is oxidized by four times 

 its weight of permanganate of potash, there are produced car- 

 bonic acid, oxalic acid, and a certain quantity of ammonia; 

 and when the oxidation is limited by the employment of only 

 four times as much permanganate as wool, at least two new 

 acids survive, one of which (viz. cyano-propionic acid) we 

 have succeeded in obtaining in a state of purity. 



The acids arising from oxidation under these conditions are 

 met with in combination with potash, and mixed with the 

 excess of caustic potash and the carbonate and oxalate of 

 potash arising from the oxidation of the wool. The alkaline 

 liquid is first filtered from the brown oxide of manganese 

 resulting from the destruction of the permanganate ; and then 

 it is neutralized with sulphuric acid, and evaporated down to 

 crystallization. After the deposit of the greater part of the 

 sulphate of potash, the mother-liquor contains oxalate of 

 potash, which may be precipitated by the addition of weak 

 alcohol ; and after the separation of the oxalate of potash, the 

 alcoholic mother-liquor will be found to contain the potash- 

 salts of at least two new organic acids. One of these new 

 salts is very soluble in weak alcohol of 40 or 50 per cent., but 

 almost insoluble in alcohol of 84 per cent. ; and this salt, 

 which is cyano-propionate of potash, we have investigated. 



In our first attempts we endeavoured to take advantage of 

 this character in order to purify the salt ; but we afterwards 

 found that the baryta-salt admits of a most satisfactory mode 

 of treatment, and have accordingly resorted to the baryta-salt. 



We proceed to describe our experiment : — A large Berlin 

 porcelain dish, capacity from 5 to 6 litres, was fitted into a 

 water-bath and heated to 100° C. One litre of water, 300 grms. 

 of solid potash, and 100 grms. of Berlin wool were next placed 

 in the dish, and heated and stirred until the wool had com- 

 pletely dissolved in the alkaline liquid. That having been 

 done, another litre of water was added, and 400 grms. of 

 crystals of permanganate of potash were carefully and gradually 

 dropped into the alkaline liquid. The action was energetic : 

 ammonia was evolved; brown hydrated binoxide of manganese 

 was precipitated; and in a short time the colour of the perman- 

 ganate had completely disappeared. The whole was then 

 allowed to settle, and partly by decantation and partly by fil- 

 tration the alkaline liquid was separated from the brown oxide 

 of manganese. 



The alkaline liquid was nearly neutralized with sulphuric 

 acid, and evaporated until crops of sulphate of potash separated. 

 Care was taken to wash each crop of sulphate of potash with 

 repeated small quantities of water, so as to avoid loss of soluble 



