ON SOME PECULIARITIES 
IN THE 
MAGNETISM 
OF 
FERRUGINOUS BODIES. 
BY WILLIAM STURGEON, 
Lecturer to the Manchester Institute of Natural and Experimental Science, 
&e. &e. 
Communicated by Perer Cuarsz, F.R.A.S. 
(Read Nov. 29th and Dec 27th, 1842, and Feb. 2Ist, 1843.) 
1. Some of the various topics that I shall have 
to notice in this memoir, have previously been 
touched on, at different times, by several philoso- 
phers eminent in this branch of research, each of 
whom has produced data conducing more or less 
to the framing of a true theory of magnetism. 
2. From the time that the diurnal vicissitudes 
of terrestrial magnetic action on the compass nee- 
dle were made known by Celcius and Graham, 
Ff 
