376 Miscellaneous Intelligence. 



the hydrogen and platina form a voltaic combination, in which the 

 former represents the zinc. Another remarkable result was obtained 

 ■with the oxidized sulphuret of platina. Placed in contact with car- 

 bonic oxide, the gas diminished to one half, and became carbonic 

 acid; hence it is decarbonized by the solid substance. In a supple- 

 ment to the paper just abstracted, in which M. Dobereiner describes 

 the mode of making the experiment, as we have stated, by a jet of 

 hydrogen, he mentions also, that he had applied it to the construction 

 of a new apparatus for procuring fire. 



In a further communication to the public *, on this subject, M. 

 Dobereiner says, that the energy of hydrogen is so much increased 

 by the presence of platina in powder, that it will in a few minutes 

 completely separate one part of oxygen, from 99 of nitrogen, an 

 effect which the strongest electrical spark will not produce. In these 

 experiments, platina in powder is mixed with potters'clay, moistened, 

 and made into small balls, about as large as a pea, these are dried 

 and then heated to redness, one of these balls, weighing from 2 to 6 

 grains, will convert any quantity of detonating gas into water, and 

 may be employed above a thousand times, if dried carefully after 

 each operation. — The compound gases, containing hydrogen, do 

 not combine with oxygen, when in contact with platina. A jet of 

 hydrogen on the platina, precipitated by zinc from a solution, made 

 it red hot, with a crackling noise and sparks; this powder is a mix- 

 ture of platina and its oxide, and converts alcohol, when oxygen is 

 present, into acetic acid. Nickel prepared from the oxalate, has 

 the property of converting oxygen and hydrogen gases slowly into 

 water. 



MM. Dulong and Thenardt, have verified the experiment, of 

 the ignition of platina by a jet of hydrogen, and have added some 

 other facts on the same subject. They remarked, as M. Dobereiner 

 had done, that introduced into a mixture'of oxygen and hydrogen, 

 it determined the combination of the gases sometimes with ignition ; 

 that the platina, strongly calcined, loses the property of becoming in- 

 candescent, but still slowly causes condensation ; that finely-divided 

 platina, obtained by other means, or wires, or lamina?, had no action 

 at common temperatures, but that very thin leaf platina crumpled up 

 together acted instantly, although the same leaf rolled round a cylin- 

 der of glass, or suspended freely in the gases, had no action ; but the 

 leaves, "wires, powder and plates, all acted slowly at temperatures 

 between 400° and 5?2° F. Palladium in thin pieces acted at an 

 elevated temperature, as well as platinum of the same thickness. 

 Rhodium caused the formation of water at about 4rj4° F. Gold and 

 silver, in leaf, acted at a temperature somewhat under that of boiling 

 mercury. 



* Annates tie C/iimie, xxiv. 91. Bib. Univ. xxiv. 54. 

 f Annates de Chimk, xxiii. 440. 



