Prof. Dccbereiner on his new Experiments. 291 



oxygen, and the volume of the mixture be rather large, the 

 platinum becomes red-hot. I could not but coiiclude, from 

 this most remarkable phasnomenon, that the finely-divided 

 metallic platinum which is produced by the igneous decom- 

 position of the ammonia-muriate, would perhaps exhibit this 

 singular effect upon the detonating nuxture ; and, to my great 

 satisfaction, this supposition was confirmed by the experiment. 

 Someplatinum powder, prepared from thesali'neprecipitate just 

 named, was wrapped up in white blotting-paper, antl brought 

 into contact with the hydrogen gas; and, as might be expect- 

 ed, no absorption took place, nor any other perceptible mu- 

 tual action. Upon this I caused atmospheric air to have ac- 

 cess to the platinum powder in contact with the hydrogen, 

 and after the lapse of a few moments that remarkable reac- 

 tion took place ; viz. the gas diminished in volume ; and in ten 

 minutes all the oxygen of the atmospheric air admitted had 

 condensed with the hydrogen into water. I afterwards mixed 

 pure oxygen gas with the hydrogen in contact with the pla- 

 tinum; a condensation of both mimediately took place, and the 

 platinum heated to such a degree, that the paper in which it 

 was wrapped was suddenly charred. These experiments were 

 repeated about thirty times on the same day, July 27, 1823, 

 on which I discovered this remarkable phfenomenon, and 

 with the same success every time. 



What useful applications of this discovery may be made in 

 oxymetry, the synthesis of water, &c,, 1 shall hereafter state 

 more circumstantially. I shall at present merely observe, in 

 conclusion, that the entire phasnomenon must be considered 

 as an electric one, that the hydrogen and platinum form a vol- 

 taic combination, in which the former represents the zinc; — the 

 first established instance of an electric alternation formed by 

 an elastic fluid and a solid substance; the application of which 

 will lead to further discoveries. 



I obtained another interesting result in an experiment on 

 the relation of the oxidized suphuret of platinum to carbonic 

 oxide. I found that this gas is always diminished to half its 

 bulk when it comes into contact witli the sulphuret, and tliat 

 the remaining gas is not carbonic oxide, but carbonic acid. 

 The carbonic oxide gas is therefore decarbonized by the oxidized 

 sulphuret of platinum, and thereby changed into carbonic acid. 



SUPPLEMENT*. 



I send you a short supplement to tlie paper communicated 

 to you some days ago, on the newly discovered properties of 



* From a letter of Profcwor Doebereiner to Professor Schweigger, d.ited 

 Jtiia. A lit; 3. ^^~^- 



O o 2 several 



