Supposed Polarity of Diamagnetic Bodies. 189 
2642. It appeared to me that many of the results which had 
been supposed to indicate a polar condition, wete only conse- 
quences of the law that diamagnetic bodies tend to go ftom 
stronger to Roca places of action (2418.); others again appear- 
ed to have their origin in induced currents (26. 2 38.) ; ; and fur- 
ther consideration seemed to indicate that the differences between 
these modes of action and that of a real polarity, whether mag- 
netic or diamagnetic, might serve as a foundation on which to 
base a mode of investigation, and also to construct an apparatus . 
that might give useful conclusions and results in respect of this ~ °} 
inquiry. For, if the polarity exists it must be in the particles 
and for the time permanent, and therefore distinguishable from | d 
the momentary polarity of the mass due to induced temporary 7 oe 
currents ; and it must also be distinguishable from ordinary mag- 
netic polarity by its contrary direction. 
2643. A straight wooden lever, 2 feet in length, was fixed by. 
an axis at one end, and by means of a crank and wheel made to, 
vibrate in a horizontal plane, so that its free extremity passed to’ ~ 
and fro through about 2 inches. Cylinders or.cores of metal or. 
other substances, 54 inches long and three-quarters of an inch di- * 
ameter, were e fixed in succession: to the end of a brass rod 2 feet + 
long, which itself was attached at: the ‘other end to the moving - 
extremity of the lever, so that the.cyhinders could be moved to 
and fro in the direction of their length. through the space. Of Ay 
inches. A large cylinder electro-magnet was,also pre a3. 3 
the iron core of which was 21 inches long and 1:7-inch in diam- es 
eter; but one end of this core was made smaller for. the ee : 
whet in its setae 1 inch of the contrel space was,0 ecup : 
the reduced end of the apo aa core which cz Fed if: 
; . the hei e both placed concentric with t 
) ned, and at such a aoe Pa 
it aighon, oly 
maapiet in 
Seen. a 
bBeqrteqponding wider! We: % & 
;), ae 4 
% 
