PROFESSOR TYNDALL ON THE DIAMAGNETIC FORCE, ETC. 
21 
These experiments can leave little doubt upon the mind, that if a magnetic body 
be attracted in virtue of its being converted into a magnet, a diamagnetic body is 
repelled in virtue of its being converted into a diamagnet. On no other assumption 
can it be explained, why the repulsion of the diamagnetic body, like the attraction 
of the magnetic one, increases in a so much quicker ratio than the force of the magnet 
which produces the repulsion. But, as this is a point of great importance, I will here 
introduce corroborative evidence, derived from niodes of experiment totally different 
from the method already described. By a series of measurenjents with the torsion 
balance, in which the attractive and repulsive forces were determined directly, with 
the utmost care, the relation of the strength of the magnet to the force acting upon 
the substances named in Tables XL, XII. and XIII. was found to be as follows : — 
Table XI. 
Spheres of native sulphur. 
Strength of magnet. 
Ratio of repulsions. 
96 
95 " 
153 
158 " 
222 
224 " 
265 
264 " 
316 
316 " 
Table XII. 
Spheres of car 
bonate of lime. 
Strength of magnet. 
Ratio of repulsions. 
134 
134 " 
172 
173 " 
213 
212 " 
259 
264 " 
310 
311 " 
370 
374 " 
Table XIII. 
Spheres of carbonate of iron. 
Strength of magnet. 
Ratio of attractions. 
66 
66 " 
89 
00 
1 14 
114 " 
141 
141 " 
In confirmation of these results I will cite a series obtained by M. E. Becquerel*, 
* Ann. de Chim. et de Phys. 3rd Series, vol. xxviii. p. 302. 
