470 Royal Society : — 



The peroxide of cumenyle is procured by a process strictly analogous 

 to that by which the peroxide of benzoyle is formed ; it has the con- 

 stitution C 20 H 22 4 . 



The peroxides of butyle and valeryle are prepared by the action of 

 hydrated peroxide of barium on the anhydrous acid. It is only 

 necessary to mix in a mortar equivalent quantities of the two sub- 

 stances. The peroxide is separated by solution in ether from the 

 water in which it is dissolved and suspended. These substances are 

 dense oily fluids, exploding slightly when heated, but not so readily 

 decomposible as the peroxide of acetyle. The analysis of the peroxide 

 of butyle, dried by chloride of calcium, gave results corresponding 

 with the formula C 8 H 14 4 . 



Calculated. Found. 



C 9 96 55*17 55-11 



H 14 14 805 8-28 



4 _64 36-78 36-61 



174 100-00 100-00 



The analysis of the peroxide of valeryle gave results corresponding 

 with the formula C 10 H w 4 . 



Calculated. Found. 



■C 10 120 59-40 59-39 



H 18 18 8-91 9-17 



4 _64 31-69 31-44 



202 100-00 100-00 



The mode of formation of these peroxides is given in the equation 



2R 2 + Ba 2 2 =2BaRO + R 2 2 . 

 These substances are decomposed as well as formed by the action of 

 the alkaline peroxide, according to the equation 



R 2 2 + Ba 2 2 = 2BaRO + 2 , 

 giving a striking example of those consecutive actions referred to in 

 a former paper as the cause of certain catalytic decompositions. 



The action of the bibasic anhydrides on the alkaline peroxides is 

 of special interest. 



When anhydrous succinic acid, lactide, or anhydrous camphoric 

 acid is mixed with an equivalent of hydrated peroxide of barium, a 

 solution is obtained possessing the most powerful oxidizing properties, 

 which bleaches indigo, evolves chlorine with hydrochloric acid, and 

 oxidizes the protosalts of iron and manganese, but which does not 

 discolour permanganic acid, or give with chromic acid the .blue colour 

 formed by peroxide of hydrogen. When boiled, the solutions evolve 

 oxygen, and afterwards contain a salt of the acid employed — in the 

 case of succinic acid, giving a crystalline precipitate of succinate of 

 barium, and in the case of camphoric acid, giving with acetate of 

 lead a precipitate of camphorate of lead. These solutions are in a 

 state of continual decomposition. Only in one instance, that of cam- 

 phoric acid, was it found possible to analyse the substance, and that 

 only by indirect processes. The oxygen contained in the organic 

 peroxide was estimated in a measured portion of the solution by means 

 of a standard solution of iodine ; the camphoric acid formed on 

 boiling was determined by precipitation with acetate of lead in another 



