246 



Prof, von Kohell upon Galvanography. 



leaden disc is shown in 

 connection with the base- 

 plate by means of the 

 binding screw, o ; k in- 

 dicates the height of the 

 cupreous solution, and z 

 that of the exciting fluid 

 in the tamborine. 



Fig. 13. 



Fig. 14. 



Fig. 15 represents a decomposing-cell apparatus. The copper 

 plate aa in the vessel with the tamborine A, is connected by 

 means of the strip with the copper plate gg of the vessel B, (fig. 

 15.) The leaden disc e is connected by a metal strip with the 

 copper plate ff of the vessel B, and upon this latter plate lies the 

 painted plate hh. In this arrangement the copper plate gg is 

 taken up and consumed in the same ratio that copper is deposited 

 upon hh, and upon the parts of j^ not insulated by a coat of wax. 



Fig. 15. 



B A. 



The sulphate of copper in the vessel A, undergoes decomposi- 

 tion at the same time, and aa becomes coated with a galvanic 

 deposit of that metal. Two painted plates, one lying on aa and 

 one on ff, may therefore be coated simultaneously ; but the ac- 

 tion proceeds much more slowly when this decomposing cell is 

 employed, than when we have recourse to the apparatus repre- 

 sented in fig. 13. In using this arrangement, care must be taken 

 that the plate ff is not in contact with the surrounding copper 

 plate gg. 



