230 MAGNETO-ELECTRICAL DECOMPOSITION. 



in the galvanic battery, a disturbance of the electricity 

 of the solution of copper, silver, or gold, is produced, 

 and the metal is deposited ; but, instead of allowing the 

 acid in combination to escape, it has presented to it 

 some of the same metal as that revived, and, conse- 

 quently, it combines with it, and this compound, being 

 dissolved, maintains the strength of the solution.* A 

 system of revival, or decomposition, is carried on at one 

 pole, and one of abrasion, or more correctly speaking, of 

 composition and solution, at the other. By taking 

 advantage of this very extraordinary power of electricity, 

 we now form vessels for ornament or use, we gild or 

 silver all kinds of utensils, and give the imperishability 

 of metal to the most delicate productions of nature 

 her fruits, her flowers, and her insects ; and over the 

 finest labours of the loom we may throw coatings of gold 

 or silver to add to their elegance and durability. Nor 

 need we employ the somewhat complex arrangement of 

 the battery : we may take the steel magnet, and, by 

 mechanically disturbing the electricity it contains, we 

 can produce n current through copper wires, which may 

 be used, and is extensively employed, for gilding and 

 silvering.t The earth itself may be made the battery, 

 and, by connecting wires with its mineral deposits, cur- 

 rents of electricity have been secured, and used for the 

 production of electrotype deposit. J 



* See Spencer, Instructions for the Multiplication of works of 

 Art in Metal by Voltaic Electricity. Novelties in Experimental 

 Science: Griffin, Glasgow Elements of Electro-Metallurgy : b} 

 Alfred Smee, Esq. 



f The magneto-electrical machine is employed in Birmingham 

 for this purpose ; but I am, informed by Messrs. Elkington that 

 they do not fiud it economical, or rather that the electro-precipita- 

 tion is carried on too slowly. 



I This has been done by Mr. Eobert Were Fox, at a mine near 

 Falmouth. By connecting two copper wires with two lodes, and 

 bringing them, at the surface, into a cell containing a solution of 

 sulphate of copper, this gentleman obtained an electrotype copy of 

 an engraved copper-plate. 



