Examination of the Peroxide of Manganese. 85 



Dr. John passed chlorine through a solution of three hundred 

 grains of protochloride, dissolved in 12 oz. water, cooled to 41°. 

 The liquid gradually congealed as the operation proceeded, and 

 produced a yellowish crystalUne mass, which melted at a tem- 

 perature a little above 41°. It was decomposed by evaporation.* 

 This may only have been the perchloride, surrounded by liquid 

 chlorine, for Avhen I repeated this experiment, at a temperature 

 above 41°, I obtained a yellowish crystalline masS; which, how- 

 ever, on being placed between blotting paper to dry it, proved 

 that a yellow liquid imparled that color to the salt, which itself 

 was pink. I did not however observe that it was decomposed 

 by evaporation. 



Sulphurous acid. — This acid has no action upon the peroxide, 

 even when passed over it in a heated tube ; and with the deut- 

 oxide it forms proto-hypo-sulphate. I do not think that the per- 

 sulphite can be formed unless by double decomposition with 

 some other salt. 



Carbonic acid. — It has no action upon the peroxide, and as 

 far as I have observed, it cannot be made to combine with it. 

 The brown substance mentioned by Thomson, (Chem. Inor. 

 Bodies, Vol. II,) and formed by decomposing the persulphate of 

 manganese by carbonate of potassa, is most probably an hydrate 

 of one of the oxides. 



Phosphoric acid. — When digested upon peroxide, this acid 

 forms a pink solution, giving the per reaction with tests, and 

 which upon evaporation leaves an uncrystallizable pasty mass, of 

 a pink or violet color, which becomes colorless in a short time, 

 most probably by decomposition. 



Boracic acid. — The borate can be readily formed by dissolving 

 the peroxide in boracic acid. The solntion thus formed by evap- 

 oration leaves a whitish crystalline mass, soluble both in nitric 

 and muriatic acid. 



Arsenious acid. — When peroxide is digested in arsenious acid, 

 they unite and form a soluble pinkish white salt. 



If bi-arsenite of potassa be digested upon peroxide of man- 

 ganese, it forms a double salt, being arsenite of manganese and 

 potassa. 



* Berzelius, Traite de Chimie, Tom. IV, p. 170. 



