Action of Platinum-black on Peroxide of Hydrogen. 281 
1. Guaiacum resin solution gives with free as well as com- 
bined ozonized oxygen a very delicate blue colour, while the 
active oxygen of peroxide of hydrogen and of the antozonides 
are without action upon it. But when platinum-black is added 
to a solution of guaiacum which contains peroxide of hydrogen, 
an intense blue colour is formed. 
2. Ether dissolves peroxide of hydrogen without being affected 
by it, while free or combined ozonized oxygen at once renders it 
acid. Now if an ethereal solution of peroxide, and which at 
once gives an intense blue with chromic acid, be agitated with 
platinum-black, it loses the property of giving a blue with 
chromic acid, and soon has an acid reaction. 
3. Peroxide of hydrogen decolorizes indigo solution very 
slowly, while it is instantaneously decolorized by free or com- 
bined ozonized oxygen. If, however, a mixture of indigo solu- 
tion and peroxide of hydrogen be agitated with platinum-black, 
the solution is rapidly decolorized. 
Hence it appears that the @ of the peroxide produces the 
same actions as the 0 of ozonized oxygen. May it not then be 
assumed that platinum can change the positively active oxygen 
of the peroxide into the negatively active state, without making 
any assumption as to how this is effected. On this assumption 
the © of the peroxide in immediate contact with the platinum 
becomes changed into negatively active oxygen, O; this O would 
neutralize a portion of ® and form ordinary oxygen; in other 
words, the layers of peroxide next the platinum would form ordi- 
nary oxygen and water. After this catalysis, the @ of another 
portion of peroxide in contact with the platinum would be 
changed into 0, which would decompose with another portion 
of peroxide of hydrogen into water and oxygen, and soon, A 
small quautity of platinum might thus decompose an indefinite 
quantity of peroxide. 
To saturate ether with peroxide of ethyle, Sch6nbein uses the 
followig method:—Dilute hydrochloric acid is added to a 
gramme of peroxide of barium until the liquid is neutral; the 
mixture is then agitated with 40 grms. of pure ether and allowed 
to stand, ‘This ethereal solution, poured off from the chloride of 
barium, turns chromic acid blue, decolorizes permanganate of 
potash, and has indeed all the reactions of peroxide. It may be 
distilled without alteration. When a volume of it is shaken with 
four volumes of water, the peroxide of hydrogen is completely 
removed. Potash removes it still more quickly. 
Niépce de Saint-Victor and Corvisart* describe the following 
instances of the peculiar influence which the sunlight exerts in 
modifying and changing amylaccous substances. 
* Comptes Rendus, September 5, 1859. 
