On the Development of Hydrogen from the Anode. 269 



The oxygen of the protoxides of the preceding analysis amounts 

 to ] 2*342 per cent. ; but it would be fallacious to form any 

 opinion as to the composition of the whole, so long as we are not 

 acquainted with the constituent minerals that compose it. 



Collecting together into one view the preceding results, we 

 find — 



4. Miner alogical Composition of the Dhurmsalla Meteorite. 



,.40 /"Iron . 6-88 

 \Nickel . 1-54 



2. Protosulphuret of iron . . . 5*61 



3. Chrome-iron* 4*16 



4. Chrysolith (Peridot or olivine) 47*67 



5. Minerals insoluble in muriatic"! OA 1 , 



acid J 84 ' 14 



100-00 



Trinity College, Dublin, 



1. Nickel-iron 8- 



June 1, 1866. 



XXXIV. On the Development of Hydrogen from the Anode. 

 By Professor W. Beetz-j-. 



IP a solution of an alkali or an alkaline earth be decomposed 

 between magnesium electrodes, the negative wire undergoes 

 no change either in appearance or weight, whilst the positive 

 wire is dissolved with simultaneous evolution of hydrogen. The 

 development of this gas under such circumstances was observed 

 by Wohler and BuffJ in the case of another metal, aluminium ; 

 the process, however, was rendered more intricate by the pre- 

 sence of a considerable quantity of silicon, and the consequent 

 formation of siliciuretted hydrogen. The greater simplicity of 

 the action when magnesium is used recommends the employ- 

 ment of this metal for observations on this unusual electrolysis ; 

 for by its means we may not only trace the causes which act in 

 this case, but likewise those influencing the phenomena observed 

 when the terminals consist of aluminium wires. 



The magnesium wire made use of in the following experi- 

 ments was from the works of Johnson, Matthey, and Co., of 



* The quantity of chrome found in this meteorite is unusually large, 

 being represented by 2'84 per cent, of Cr O 3 , and by 4*16 per cent, of 

 FeO, Cr 2 O 3 ; yet it is not without precedent, for in the meteoric stone that 

 fell at Nobleborough, Maine, U.S.A., on the 7th of August, 1823, Web- 

 ster found 4 per cent, of Cr 2 O 3 . 



t Translated by Dr. W. Flight from Poggendorfr's Annalen der Physik 

 und Chemie, No. 1, 1866. 



% Ann. der Chem. und Pharm. vol. ciii. p, 218. 



