730 Proceedings of the Royal Society of Edinburgh. [Sess. 
turn supported by glass beads which till the lower part of the tube. The 
cathode is of platinum, and is placed inside the porous cell D. The tube is 
now filled to the point e with concentrated hydrochloric acid. Upon passing 
a current of, say, 8 amperes, through the cell from the regular 110 volt 
circuit, the platinum goes rapidly into solution, and the chloroplatinic acid 
formed can be siphoned off at F. 
Fig. 2. 
This apparatus was somewhat modified for the present purpose. In the 
first place, as it was desirable to have as small a surface of glass as possible 
in contact with the solution, the glass beads as a support for the anode were 
not used. Instead of these, several depressions were made in the tube at the 
points e e, as shown in fig. 2, and the anode supported by these. Secondly, it 
was found impossible to obtain a porous cup from which some impurities 
