358 Messrs. Wanklyn and Cooper on the 



product; and the mother-liquor was mixed with a little alcohol, 

 which threw down a quantity of oxalate of potash. Finally 

 about 500 cub. centims. of solution, containing the new salts 

 dissolved in alcohol of 50 to 60 per cent., was obtained. This 

 solution was evaporated down to a syrup ; and at this stage 

 the exchange of barium for potassium was managed as 

 follows : — To the syrup 20 grms. of H 2 OS0 3 , previously 

 diluted with about an equal volume of water, was added, so as 

 to decompose the potash-salt. The resulting sulphate of potash 

 was separated from the new acid by means of 500 cub. centims. 

 of 84-per-cent alcohol, which dissolved the new acid and left 

 behind the sulphate of potash. The alcoholic solution was 

 mixed with 30 grms. of baryta which had been slaked, a little 

 more baryta being added so as to render the liquid alkaline. 

 The alcohol was evaporated off, and the resulting baryta-salt 

 dried up in the water-bath. After this evaporation to dryness, 

 the baryta-salt was redissolved in water, and the solution fil- 

 tered and mixed with its own volume of 84-per-cent. alcohol. 

 By this treatment a white powdery precipitate of baryta-salt 

 was obtained. The precipitate was washed with 40-per-cent. 

 alcohol, and afterwards pressed for some days between folds 

 of bibulous paper. 



The weight of the pressed baryta-salt, which retained 

 alcohol and water, was 85 grms., containing 25*1 grms. of 

 baryta-salt absolutely dry at 100° C. 



One of the objects of this precipitation by means of an equal 

 volume of 84-per-cent. alcohol (which is equivalent to the use 

 of 40 per cent, alcohol) is the removal of a new baryta-salt 

 which is very soluble in alcohol. 



The 85 grms. of pressed baryta-salt, containing 25*1 grms. 

 of baryta-salt, formula (C 4 H 4 NBa0 2 ) 2 , 3 H 2 O, are the mate- 

 rial from which we have prepared the acid and the set of salts 

 about to be described. 



In addition to the 25*1 grms. of baryta-salt, there were 

 4 grms. of baryta-salt in the alcohol employed for washing the 

 precipitate. The yield of cyano-propionate of baryta by 100 

 grms. of wool was therefore 29*1 grms. ; and, as will be seen 

 on turning to the analysis, the carbon contained by the salt is 

 7*2 grms. 



The Berlin wool employed in these experiments had been 

 previously examined; and a combustion of it had been made in 

 the ordinary hygrometric condition in which it was employed. 

 100 grms. of the wool contain 43'40 grms. of carbon. 



We have likewise made quantitative determinations of the 

 carbonic acid and the oxalic acid given by the action of four 

 parts of permanganate of potash on one part of wool dissolved 



