The uses of electrolysis in quantitative chemical analysis / by J. Wilkie.

  • Wilkie, J.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: The uses of electrolysis in quantitative chemical analysis / by J. Wilkie. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    from the battery and steam from the solutions being- electrolysed. The Copper may then become converted into nitrate and this drop into the liquids under examination. Rubbing with Oleo- naphtha or other mineral oil obviates the action of the gases upon the Copper, and the application of a lid to the basin con- taining the solutions prevents any foreign body mixing with them. One upright carries a horizontal bar, from which usually the anode, less commonly the kathode hangs ; the other carries a ring of metal in which a platinum basin rests: or it may carry a bar like its fellow for suspension of either anode or kathode where for example the whole decomposition is conducted in a beaker. The earliest kathode employed was a platinum basin, the anode consisting of a platinum wire carrying a spiral immersed in the fluid. The basin should he large for especially when made the kathode it is desirable to have as much surface as possible. It ought to hold 500 cc of fluid and be a segment of a sphere in shape. A snitable beak is very convenient, admitting after anointing with Vaseline, the safe pouring of fluid from basin to basin. Moreover a couple of lips, one at either side for con- venience of lifting into exsiccator, scales, and ring, is desirable. For the anode a couple of feet of stout platinum wire may be used, twisted at one end into a horizontal spiral of three or four turns which lies in the fluid; and may by changing the bar upon the upright be either raised out of the liquid alto- gether or brought within an inch of the platinum basin. It is necessary to provide a cover for this apparatus in the shape of a large watch glass perforated with a hole in the centre through which the wire carrying the spiral passes. It ought to be convex towards the fluid, and the hole should have a lip. In this way drops falling from the stand, and containing copper are caught. If this precaution be not taken, the experi- menter will find ever increasing quantities of that metal upon the kathode. This cover serves other purposes. Where strong currents are employed, large bubbles of gas carry portions of