160 * Prof. TjTidall on the Nature of the Force by which 



By suitably breaking and closing tlie circuit, the cube could be 

 turned 180° round and held in this new position. The axial 

 position of the ligneous fibre was one of unstable equilibrium, 

 from which, if it diverged in the slightest degree right or left, 

 the cube turned and finally set its fibre equatorial. The fol- 

 lowing is a statement of the results obtained with thirty-five 

 different kinds of wood : — 



Table I. 



The term " decided " is here used to express an action more 

 energetic than ordinary, but in no case does the result lack the 

 decision necessary to place it beyond doubt. It must also be 

 remarked that the term " strong " is used in relation to the 

 general deportment of wood ; for, compared with the action of 

 many other diamagnetic bodies, the strongest action of wood is 



