1905 - 6 .] Dr Fawsitt on Electrical Measurements on Metals. 5 
Instead of removing the polished layer by nitric acid, the rod 
was next heated for several hours at a red heat ; on inserting in 
the cell again along with Ag n the E.M.F. was found to be zero. 
Beginning again with the two rods in an annealed condition, 
one was then hammered (Ag x ) until reduced to the state of thin 
foil, which was quite elastic in comparison with the annealed rod. 
The E.M.F. of the cell Agj — AgNOg — Ag n was '012 volt, Agj 
being the negative pole. This shows that polishing and hammering 
induce a similar change in the condition of the metal as measured 
by E.M.F. methods. On heating the hammered silver rod (Agj) 
red hot, it became soft again, and the E.M.F. of the cell was 
reduced to zero. 
Experiments on other Metals. 
Experiments on gold and platinum were carried out in the 
same manner as on silver. One rod was kept throughout in the 
annealed condition. Two rods of pure gold were annealed by 
heating for several hours at a red heat, and were then introduced 
into gold chloride solution (16 grams per litre). The E.M.F. of this 
cell was measured as in the case of silver : no matter how long 
the gold was heated it was not possible, to get the E.M.F. to 
zero as expected ; however, by short-circuiting it was possible to 
reduce the small E.M.F. to zero. 
The effect of polishing or hammering one of the gold rods w r as 
such as to make it the negative pole of the cell ; the E.M.F. in 
this case is about twice as great as in the case of the silver cell, 
but the results of separate experiments varied so greatly that a 
definite figure can scarcely be given. The effect of dissolving the 
polished layer in aqua regia, or of annealing the hammered rod, 
was to reduce the E.M.F. of the cell to zero. 
AVith two rods of platinum in platinum chloride solution, 
similar results were obtained ; the polished or hammered rod is 
negative as measured against the annealed rod. 
Summary of Results. 
1. If two rods of the same metal be inserted in a solution of a 
salt of that metal, and if one of the rods be in the soft or annealed 
