OF FERRUGINOUS BODIES. aT 
for the accomplishment of extensive lateral trans- 
‘placement of the magnetic poles. 
34. These are the simple facts which have 
been developed by an extensive series of experi- 
ments; and from which there appears to be the 
same law in the lateral transplacements (33), as 
in the longitudinal transplacements (16) when 
not interrupted by temper of the metal, &c. 
35. The other class of facts (30, 31,) which do 
not accord with the general law, are not the direct 
productions of heat: they are traceable to a 
mediate cause, where laws of action are as uni- 
form as those which govern that class of pheno- 
mena which are the immediate productions of 
heat; they at all times interfere with the display 
of the latter, by urging the needle in the opposite 
direction, which conceals a portion of the direct 
effects of heat, and sometimes smothers them 
altogether. The explanation of these counter- 
acting effects being connected with other facts 
which have come under my notice, and facilitated 
by means of them, it will be well to defer that 
explanation until these other facts have been 
made known. 
Hh 
