McELFRESH. — OCCLUDED HYDROGEN IN PALLADIUM. 



327 



at the bottom of the palladium ; then by a throw of a commutator key it 

 is sent in at the lower ends of the platinum wires and out at the top 

 of the palladium. This should insure an even distribution of the hydro- 

 gen throughout the length of the wire. Two filter-paper partitions, jf, 

 in Fig. 2, are introduced, one on either side of the palladium, and are 

 held in position by having their edges caught between the glass plates 

 b and c. These filter-paper partitions serve to prevent any possible 



Figure 4. 



mixing of oxygen with the hydrogen and at the same time force all of 

 the liberated hydrogen that is not absorbed by the palladium to rise into 

 the burette, B, where its volume may be measured. 



In order to measure the resistance of the palladium wire without 

 removing it from the voltameter it is necessary that two insulated lead- 

 wires be permanently connected with each end. Accordingly (see Fig. 

 5), the upper end of the palladium wire is soldered to the middle of a 

 copper wire whose ends are carried through small holes in the hard- 

 rubber crosspiece and thence to outside connections. This copper wire 



