DR. J. HOPKINSON ON THE MAGNETISATION OF IRON. 
469 
seems to be a certain instability of something we know not what; bodies fall on one 
side practically non-magnetic, on the other enormously magnetic, but hardly any 
intermediate class exists. 
The number of actual observations made on each of the samples named has been 
very considerable, though I have not thought it necessary to set them out at length, 
as I base no general conclusion upon them. The bulk of these observations were 
made by my assistant, Mr. E. Talbot, and my pupil, Mr. Paul Dimier, to whom ray 
thanks are due for their patience and care. 
I 
3 P 
MDCCCLX XXV. 
