Intelligence and Miscellaneous Articles. 337 



experiments described by the lecturer, this abstraction was to a 

 great extent avoided by reducing the metallic masses to thin laminae ; 

 and thus the very experiments adduced by Professor Forbes against 

 the theory supported by Professor Faraday appear, when duly con- 

 sidered, to be converted into strong corroborative proofs of the cor- 

 rectness of the views of the philosopher last mentioned. 



XXXIV. Intelligence and Miscellaneous Articles. 



ELECTRO-DEPOSITION OF ALUMINIUM AND SILICIUM. 

 BY GEORGE GORE, ESQ. 



To the Editors of the Philosophical Magazine and Journal. 



8 Broad Street, Birmingham, 

 Gentlemen, February 24, 1854. 



1 ENCLOSED are two specimens of sheet copper, one coated with 

 -^ metallic aluminium and the other with silicium, by electro- 

 deposition process ; and if the following simple statement of the 

 manner in which they were obtained is worthy of a place in your 

 Magazine, I shalfbe happy to have it published. 



To obtain the aluminium, I boiled an excess of dry hydrate of 

 alumina in hydrochloric acid for one hour, then poured off the clear 

 liquid, and added to it about one-sixth of its volume of water ; in 

 this mixture I placed an earthen porous vessel contaiuing one mea- 

 eure of sulphuric acid to twelve measures of water, with a piece of 

 amalgamated zinc plate in it. In the chloride of aluminium solution I 

 imtaersed a piece of copper of the same amount of immersed metallic 

 Burface as that of the zinc, and connected it with the zinc by means 

 of a copper wire, and set it aside for several hours ; when on exami- 

 ning it, I found it coated with a lead-colour deposit of aluminium, 

 which when burnished possessed the same degree of whiteness as 

 platinum, and did not appear to tarnish readily by immersion in 

 cold water or in the atmosphere, but was acted upon by sulphuric 

 or nitric acids, either concentrated or dilute. 



I found that if the apparatus was kept quite warm, and a cop- 

 per plate much smaller than the zinc plate was used, the deposit 

 appeared in a very short time, in several instances in less than half 

 a minute. Also J found that if the chloride solution was not diluted 

 with water, the deposit was equally, if not more rapid. 



I have also succeeded in obtaining a quick deposit of aluminium 

 in a less pure stn*'e by dissolving ordinary " pipe-clay " in boiling 

 hydrochloric acid, and usihg the supernatant clear solution undiluted 

 with water in the i)lace of the before-mentioned liquid. A similar 

 deposit of aluminium was also obtained from a strong aqueous solu- 

 tion of acetate of alumina ; likewise from a saturated aqueous solu- 

 tion of ordinary " potash alum," but rather slowly ; with each of 

 tl»e solutions named, the deposit was hastened by putting either one, 

 two, or three small Smee's batteries in the circuit. 



