WRITINGS OF JOSEPH HENRY. 



[1824- 



Fig. 4, is designed to show the 

 action of two conjunctive wires on 

 each other ; A B, is a thick multi- 

 plying coil, with galvanic plates 

 attached, in the same manner as 

 shown in Fig. 2 ; c cZ, is a lighter 

 coil, with a double cylinder, pre- 

 cisely similar to Fig. 3, and sus- 

 pended within the other by a fibre 

 of silk, passing through a glass 

 tube, (a) the end of which is in- 

 serted into an opening (6) in the 

 upper side of A B ; e J are two 

 wires supporting the glass tube. 

 When the cylinder ^ and the plates 

 C are placed in vessels of acidu- 

 lated water, the inner coil will im- 

 mediately arrange itself so that the 

 currents in both coils will circulate 

 the same way : if the vessel be re- 

 moved from C,and D placed in the 

 fluid, the coil c d will turn half- 

 way round and again settle, with the currents flowing in 



