1823.] Scientific hitelligence, 465 



mixture be rather large, the platinum becomes red-hot. I could not 

 but conclude, from this most remarkable phgenomenon, that the 

 finely-divided metallic platinum which is produced by the igneous, 

 decomposition of the ammonia-muriate, would perhaps exhibit this 

 singular effect upon the detonating mixture ; and, to my great satis- 

 faction, this supposition was confirmed by the experiment. Some 

 platinum powder, prepared from the saline precipitate just named, 

 was wrapped up in white blotting-paper, and brought into contact 

 with the hydrogen gas ; and, as might be expected, no absorption 

 took place, nor any other perceptible mutual action. Upon this I 

 caused atmospheric air to have access to the platinum powder in con- 

 tact with the hydrogen, and after the lapse of a few moments that 

 remarkable reaction 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 platinum ; a 

 condensation of both immediately took place, and the platinum heated 

 to such a degree, that the paper in which it was wrapped was sud- 

 denly charred. These experiments were repeated about thirty times 

 on the same day, July 27, 1823, on which I discovered this remark- 

 able phsenomenon, and with the same success every time. 



What useful applications of this discovery may be made in oxyme- 

 try, the synthesis of water, &c., I shall hereafter state more circum- 

 stantially. I shall at present merely observe, in conclusion, that the 

 entire phgenomenon nmst be considered as an electric one, that the 

 hydrogen and platinum form a voltaic combination, in which the 

 former represents the zinc ;—*the first established instance of an elec- 

 tric 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 rela- 

 tion of the oxidized sulphuret of platinum to carbonic oxide. I found 

 that this gas is always diminished to half its bulk when it comes into 

 contact with the sulphuret, and that the remaining gas is not carbonic 

 oxide, but carbonic acid. The carbotiic oxide gas is therefore decar- 

 bonized by the oxidized sidphuret of platinum^ and thereby changed into 

 carbonic acid. 



SUPPLEMENT.* 



I send you a short supplement to the paper communicated to you 

 some days ago, on the newly discovered properties of several prepa- 

 rations of platinum. That the continuation of the experiments on 

 this interesting subject would lead to new discoveries, was to be ex- 

 pected. 1 merely mention to-day, that I have succeeded in making 

 the observed dynamic relation of the platinum powder to ihe hydro- 

 gen gas, appear in a very splendid manner by experiment. If hydro- 

 gen gas be sufiered to issue from a gasometer through a capillary tube 

 bent downwards, upon the platinum contained in a small glass funnel 

 sealed at the bottom, so that the stream may mix with the atmo- 

 spheric air before it comes in contact with the platinum, which is 

 effected when the tube is from 1 to 1 V or 2 inches distant from the 

 platinum, the latter almost instantly becomes red- and white-hot, and 



• • From a letter of Professor Doebereiner to Professor Schweigger, dated Jena, 

 August 3, 1823. 



ISew Series, voi.. vi. 2 h 



