626 EXPERIMENTAL INVESTIGATION OF THE 
the magnetic actions of bodies, whether of a 
ferruginous or a non-ferruginous character. 
Under these circumstances, any further investi- 
gations of mine, or of any other experimental 
enquirer, could be productive of nothing more 
than the developement of a few novel facts in 
addition to those already recorded, or the appli- 
cation of some of them to novel and useful 
purposes. 
2. It frequently happens, however, in experi- 
mental inquiries of this kind, that the different 
modes of investigation resorted to by different 
philosophers, are not only productive of new facts, 
but are the means of developing new laws, and of 
leading to theoretical views differing considerably 
from those previously entertained for the explana- 
tion of phenomena which had long been grafted 
into the history of science. And it must be 
acknowledged that, whether new facts be added 
to the old stock—the application of any of them 
to useful purposes discovered—or that novel and 
more exact views for the explanation of those 
facts be developed, an additional step in the 
advancement of science would thus be securely 
established ; and it is solely from a hope that by 
some of these means the present memoir will 
