46 M. Thenardonthe [Jan. 



almost as soon as the action occurred; the metal did not appear 

 to be oxidized. If the peroxide were sensibly acid, it acted 

 much less readily. 



Pailadium in powder, and peroxide containing only nine 

 volumes of oxygen. The same phenomena as with silver, 

 excepting that the disengagement of oxygen was rather less 

 rapid. 



IViodium in powder, prepared by calcining the ammoniaco- 

 muriate of rhodium, with pure and diluted peroxide. The action 

 of this metal is nearly the same as that of palladium, excepting 

 that the presence of a little acid did not retard it so much. 



Lead reduced to fine fihngs and pure peroxide. Action at 

 first slow, but which gradually increases, and finishes in a few 

 minutes, becoming extremely strong, and exciting much heat. 

 All the oxygen is disengaged, and I do not think that the lead 

 is oxidized. 



Lead reduced to fine filings, and peroxide containing nine 

 volumes of oxygen. Action at first weak, gradually becoming 

 stronger, and then the bubbles of oxygen are rapidly hberated, 

 and raise the metallic particles. Is there not a little oxide 

 formed, which, it will be hereafter seen, readily decomposes 

 oxygenated water? It is certain, that at the expiration of an 

 hour, no oxygen remains in the liquor. 



Bismuth J well powdered, and pure peroxide. The same phe- 

 nomena as with lead. 



Bismuthy well powdered, and liquor containing only nine 

 volumes of oxygen. The action is extremely slow. Bubbles 

 are only occasionally given out ; but at the end of some hours, 

 the liquor was always deoxidized. The metal did not appear to 

 be oxygenated. 



Mercury and pure peroxide. The same phenomena as with 

 lead and bismuth, provided the solution be not acid ; when it 

 contains a little sulphuric acid, there is also formed a red sub- 

 stance, which is probably a subsulphate. 



Mercury and peroxide containing only nine volumes of 

 oxygen. Very evident disengagement of gas, especially when 

 the solution is rather alkahne than acid : the mercury is not 

 oxidized : one drop of a very weak acid is sufficient to stop the 

 disengagement. 



Cobalt, nickel, cadmium, copper. Very weak action. 



Of the Metals tvhich decompose the Peroxide of Hydwgeri, absorb- 

 ing Part of the Oxygen, and disengaging the remainder. 



Arsenic in powder and pure peroxide. Sudden and most 

 violent action; flame produced by the combustion of the arsenic, 

 which, acidifying, prevents the whole of the oxygen from being 

 disengaged or absorbed, at least instantaneously ; consequently 

 very great disengagement of heat. When the peroxide is in 

 excess, all the arsenic becomes acid, and is dissolved. 



4 



