repetition of M. Arago's experiments on mugnetism^ &c. 473 
TABLE V. 
Name of the revolving 
substance. 
Mean of deviations 
screwing and un- 
screwing. 
Ratio of force to that 
of copper. 
Copper 
O / 
28 54 
1 .00 
Zinc 
26 42 
0-93 
Tin 
12 54 
0.46 
Lead 
7 0 
0.25 
Antimony - 
2 27 
O.O 9 
Bismuth - 
0 32 
0.02 
Agreeing as nearly as could possibly have been expected 
with the foregoing. 
10. The extension of the same mode of examination to 
other simple and compound bodies, differing widely in their 
relations to heat, electricity, gravity, and other chemical and 
mechanical agents, presents an extensive and most interest- 
ing field of enquiry, and one which promises a nearer insight 
into the nature of magnetism, both permanent and transient, 
than we have yet attained. Our examination has necessarily 
been limited, partly from the imperfection of our apparatus, 
but chiefly from want of time ; indeed on reperusing the 
present notice, it is impossible not to regard it as in many 
respects imperfect and hasty ; and nothing certainly but the 
strong interest of the subject, and the uncertainty whether we 
shall have it in our power to prosecute it with greater assiduity 
in future, could induce us to present our results in their pre- 
sent state. Such as they are, however, we shall give them. 
11. Of the other metals, silver appears to hold a high rank, 
and gold a very low one in the scale of magnetic energy. 
Indeed the latter metal rendered standard by copper was 
