294 Proceedings of Royal Society of Edinburgh. [sess. 
In this connection I would draw attention to a paper published 
in the Philosophical Magazine for June 1904, bearing on a cognate 
line of research. In that paper Dr E. P. Harrison shows that 
pure nickel uudergoes curious changes of length as the temperature 
approaches the temperature at which its magnetic properties are 
lost. This is strictly analogous to the behaviour of iron at 
red heat, as discovered long ago by Gore. Tait found that 
the thermo-electric properties of iron had peculiarities which 
occurred at this same temperature ; and that similar thermo- 
electric peculiarities were possessed by nickel. He tried, but un- 
successfully, to find a Gore effect in nickel at a temperature of 
400°. This has now been very satisfactorily accomplished by Dr 
Harrison. It is possible, however, that the result obtained by 
Dr Harrison may be partly due to variation in the magnetic strain 
caused by the circular magnetization accompanying the strong 
current used for keeping the nickel wire at the required high 
temperature. 
As to the cause of the curious effects described in this note, 
more than one hypothesis might be advanced, but it would be 
premature to attempt any complete discussion until further facts 
are made out. These I hope to communicate in due course. 
( Issued separately July 30 , 1904 .) 
