1822.] Properties of Peroxide of iT^/drogen, 4S 



metals were tried in this manner, exceptiiiig uranium, titanium, 

 cerium, barium, strontium, calcium, lithiuim, and the metals of 

 the earths. 



Of the Metals which decompose the Peroxide of Hydrogen, and 

 disengage the Oxygen without under going any Change, 



Silvery finely divided, procured by the Tecent decomposition 

 of nitrate of silver by copper, and pure pe roxide of hydrogen. 

 Sudden and violent action, the extrication c>f heat so great, that 

 the tube became burning hot ; the silver xetained its metallic 

 state, and all the oxygen was instantly disengaged. 



Silver J finely divided, and peroxide cont€ lining nine times its 

 volume of oxygen. Sudden and brisk effervescence, no sensible 

 heat : the silver was not oxidized ; the action was soon over, and 

 all the oxygen was disengaged. The tube i s not heated unless 

 the peroxide contains at least 30 times its volume of oxygen. 



Silver precipitated from the solution of nitrate of silver by 

 copper, but the parts of which were become k^ss finely divided by 

 drying. Action upon the peroxide much we aker than with the 

 finely divided silver of the two preceding experiments. 



Silver in filings. Action much weakei* than the last. 



Silver in mass. Action extremely weak compared to that with 

 divided silver. 



Platina in fine powder, prepared from the aiimioniaco-muriate, 

 calcined with common salt, and pure peroxide of hydrogen^ 

 Phenomena similar to those with silver ; the action, perhaps, a 

 little stronger. I do not conclude from this, that the platina 

 itself acts more upon the peroxide than silvei' ; for in order to 

 ascertain this, the state of division of the metaUic particles, 

 which so much influences their action, must be equal. 



Platina in fine powder, and peroxide contain] ng nine times its 

 volume of oxygen. Phenomena similar to those with silver. 



Platina in filings and in mass. The same action upon the? 

 peroxide as with silver in fihngs and in mass. 



Gold, finely divided, procured from the decomposition of 

 muriate of gold by sulphate of iron. The same action upon the 

 pure and diluted peroxide as with silver arid platina, provided 

 the liquid be not sensibly acid. 



Gold in filings and in mass. The same action upon the per- 

 oxide as with silver in filings and in mass. 



Osmium in black powder and pure peroxide. Action more 

 violent than with the preceding metals, which may depend upon 

 the metal being more finely divided : in other respects, the phe- 

 nomena were similar ; the same effects, except as to intensity, 

 with osmium and diluted peroxide as with platina and silver. 



Palladium in powder, prepared by calcining ammoniaco- 

 muriate of palladium, and pure peroxide. Pteady aad very hvely 

 action, but less so than that of platina, silver, gold, and osmium ; 

 great extrication of heat. All the oxygen was disengaged^ 



