TEANSACTIONS OF SECTION G. 789 



Both at Swansea and Widnes immense quantities of copper, in spite of the 

 restrictive operations of the copper syndicate, are being produced by electro-de- 

 position. Copper steam pipes for boilers are now being built up of great firmness, fine 

 texture, and considerable strength by Mr. Elmore at Cockermouth, by electro- 

 deposition on a rotating mandril in a tank of sulphate of copper. By this process 

 one ton of copper requires only a little more than one ton of coal to raise the 

 requisite steam to complete the operation. 



It has been shown that the electrolytic separation of silver from gold by similar 

 methods is perfectly practicable. The value of the material to be dealt with may 

 be gathered from the fact, communicated to the ' Gold and Silver Commission ' now 

 sitting, that nearly 90,000,000 ounces of silver are annually produced, and the 

 greater portion of this amount contains sufficient gold to render refining remunera- 

 tive. Although the old acid process of 'parting' gold and silver remains prac- 

 tically undisturbed, there seems no reason to doubt that in the future electricity 

 will render us good service in this direction as it has already in the puiification of 

 copper. 



There is not much actual progress to report in the extraction of gold from its 

 ores by electrical agency. The conversion of gold into chloride of gold by the 

 direct, or indirect, action of chlorine is employed on a very large scale in [Grass 

 Valley] California and elsewhere. This fact has led to well-directed efforts to 

 obtain, by electrolytic action, chlorine, which should attack finely divided gold 

 suspended (with the crushed ore) in the solution from which the chlorine was 

 generated, the gold, so converted into soluble chloride, then being deposited on a 

 cathode. The process would seem to be hopeful, but is not as yet a serious rival to 

 the ordinary chlorination method. 



In the amalgamation of gold ores much is expected from the possibility of 

 keeping clean, by the aid of hydrogen set free by the electric current, the surfaces 

 of amalgamated plates. 



It is well known that the late Sir W. Siemens considered that the electric arc 

 might render good service in the fusion of metals with high melting-points, and he 

 actually succeeded in melting 96 ounces of platinum in 10 minutes with his electri- 

 cal furnace. The experiments were interrupted by his untimely death, but in the 

 hands of Messrs. Cowles the electric arc produced by 5,000 amperes and 500 horse- 

 power is being employed on a very large scale for the isolation of aluminium (from 

 corundum), which is immediately alloyed (in situ) with copper or iron, in the 

 presence of which it is separated. 



The heating power of large currents has been used by Elihu Thomson in the 

 United States, and by Bernardos in Russia, to weld metals, and it is said to weld 

 steel without aff"ecting its hardness. It has even been proposed to weld together 

 in one continuous metallic mass the rails of our railways so as to dispense entirely 

 with joints. 



The production of chlorine for bleaching and of iodine for pharmaceutical 

 purposes, the economical production of oxygen, are also processes now dependent 

 on the electrolytic effect of the electric current. 



It is almost impossible to enumerate the various general purposes to which 

 electricity is applied to minister to our wants, and to add to our comforts. Every 

 one appreciates the thorough efficiency of the trembling electric bell, while all will 

 sooner or later derive comfort from the perennially self-winding electric clock. 

 Correct mean time is distributed throughout the length and breadth of the land by 

 currents derived from Greenwich Observatory. Warehouses and shops are fitted 

 with automatic contact pieces, which, on any undue increase of temperature due to 

 fire, create an alarm in the nearest fire station ; and at the corner of most streets a 

 post is found with a face of glass, which on being broken enables the passer-by or 

 the watchful and active policeman to call a fire engine to the exact spot of danger. 

 Our sewers are likely to find in its active chemical agency a power to neutralise 

 offensive gases, and to purify poisonous and dangerous fluids. The germs of 

 disease are attacked and destroyed in their very lairs. The physician and the 

 surgeon trust to it to alleviate pain, to curedisease, to effect organic changes beyond 

 the reach of drugs. The photographer finds in the brilliant rays of the arc lamp a 



