298 



Messrs. L. Mond and C. Langer. 



[June 20, 



Fig. 1. 



means of a brush with, a very thin film of platinum black, which 

 penetrates through the pores and holes of the platinum leaf, and 

 thus comes into contact with the electrolyte. The frame II is fixed 

 by means of screws between the two ebonite plates E, E', with two 

 india-rubber frames K, K' intervening, thus forming two gastight 

 chambers Gr, Gr', through which the gases to be used are let by the 

 tubes 0, 0' and H, IT. 



Fig. 2. 



The second construction consists of a number of elements each of 

 which is composed of two frames of lead and antimony consisting of 

 a broad edge R, conducting strips A, and flaps E with holes and 

 channels 0, H, which form the inlets and outlets for the gases. These 

 frames are coated with an insulating layer a of a mixture of gutta- 

 percha, beeswax, resin, and jDaramn. Between the two frames we 

 insert a thin sheet S, prepared by coating a piece of cloth with 

 plaster of Paris, and made impervious round the edges by the same 

 insulating mixture, and then the open spaces formed by the conduct- 

 ing strips A are filled up with plaster of Paris mixed up with dilute 

 sulphuric acid, so as to obtain an even plate. This is now coated with 

 platinum leaf and platinum black in the same way as before described. 

 A number of these elements are put side by side or one above the other, 

 with non-conducting frames K of pasteboard intervening, so as to 



