10 



ANIMAL MECHANISM. 



manifestations of motion. Besides, the transformation of 

 motion into heat, into electricity, into light, may be proved 

 experimentally. 



Fig. 1 represents the details of the experiment. 



FIG. 1. Showing the transformation of the electricity of ,1 battery into mecha- 

 nical action, into huat, Ii 'ht, and chemical action. 



Various instruments are so arranged upon a table that an 

 electric current, engendered by a battery I', may be made to 

 pass through them.* The current is conducted in an elliptic 

 circuit, on a small square board, represented in the centre of 

 the figui-e. This circuit is formed of a thick copper wire; 

 at certain points this wire is interrupted and dipped into 

 cups of mercury, from which other wires communicate with 

 the various apparatus through which the current is to be con- 

 ducted. In Fig. 1, the metallic bridges 1, 2, 3, 4, 5, connect 

 the cups of mercury, and form a complete circuit, which the 

 current may traverse without passing through the various 

 apparatus placed ai'ound it. 



If we take away loop No. 1, the current which passed 

 through that loop is forced to traverse the elliptical circuit 

 without passing through the surrounding apparatus. But if we 



Instead of tlie single element represented in the Figure, it is necessary 

 to employ a series <>f Ijiiiisen's cells, to realise the experiments perfectly. 



