Bodies are repelled from the Poles of a Magnet. 165 



cleavages constitute the sides. If a short prism be suspended 

 in a tolerably uniform field of force, so that its rhombic ends 

 shall be horizontal, on exciting the magnet the short diagonal 

 will set equatorial, as shown in fig. 2. If the prism be suspended 

 with its axis and the short diagonal horizontal, the long diagonal 



Fig. 4. 



being therefore vertical, the short diagonal will retain the equa- 

 torial position, while the axis of the jn-ism sets axial as in fio-. 3. 

 If the prism be suspended with its long diagonal and axis hori- 

 zontal, the short diagonal being vertical, and its directive power 

 therefore annulled, the axis will take up the equatorial position 

 as in fig. 4. Now as the line which sets equatorial in diamag- 

 netic bodies' is that in which the magnetic repulsion acts most 

 strongly*, the crystal before us furnishes a perfect example of 



* Phil. Mag. Ser. 4. vol. ii. p. 177. 



