Journal . this J,1911. 210 ; Ill:!. 913). t A. IMiilip, V/W., 1914. 12, 133, and (liscussion (this J. 1014,923). 260 DESCH—THE CORROSION OF NON-FERROUS ALLOYS. [Mar; 31, 1915. The method adopted in a series of experimentswith Mr. S. ^\Tiyte* consisted in supporting asmall platinum cathode 1 cm. above the horizontalpolished surface of the specimen by means of aClassen stand for electrolytic analysis. A con-taining cell was built up of plasticine, and theelectrolyte was then introduced by means of apipette. The external electromotive force wassupplied by two dry cells. The method has now been im
Journal . this J,1911. 210 ; Ill:!. 913). t A. IMiilip, V/W., 1914. 12, 133, and (liscussion (this J. 1014,923). 260 DESCH—THE CORROSION OF NON-FERROUS ALLOYS. [Mar; 31, 1915. The method adopted in a series of experimentswith Mr. S. ^\Tiyte* consisted in supporting asmall platinum cathode 1 cm. above the horizontalpolished surface of the specimen by means of aClassen stand for electrolytic analysis. A con-taining cell was built up of plasticine, and theelectrolyte was then introduced by means of apipette. The external electromotive force wassupplied by two dry cells. The method has now been improved in detail,and a special apparatus, of the form shown inthe figure, is now used. The vertical brass rod of thestand is divided into two parts, insulated fromone another by a short section of ebonite. Thelower rod carries a brass plate, A. which may l)eclamped at any height. The small brass block,B, carries a pair of spring clips between which thespecimen, 12-5 mm. square, is held with the polished. horizontal surface upwards. The cathodeis a piece of fine platinum gauze, D, 10 , firmly attached to a vertical \vire whichpasses through a hole in the arm, C, and is held bya screw. This arm is attached to a sliding plate,which may be raised and lowered by a rack, E,and pinion, F. A scale, G, allows the height tobe adjusted. Tlie specimen, which has been pre-pared as if for microscopical examination, iscarefully freed from grease and placed in cathode is lowered until in contact with thespecimen and then raised 5 mm. A wall ofplasticine is built up to contain the electrolyte, whichis usually 1 or 2 of a 5 % solution of sodivimchloride. The two binding screws are connectedwith the source of current, which is most con-veniently a storage battery provided with a dis-tributing board and measuring instruments forelectrolytic analysis. Corrosion is then allowedto proceed for 5, 10, 20, or 60 minutes, accordingto circumstances. The wires are disconnected,
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882
