NOMOS. 1 1 



needle moved to this side or that as the direction of 

 the current changed, and always in obedience to the 

 law which rules the movements of the needle under 

 voltaic electricity. 



Ordinary electricity agrees with voltaic electricity 

 in being attended by the same signs of chemical 

 action. This has been proved by Dr. "Wbllaston, 

 and more conclusively still by Dr. Faraday. The 

 latter philosopher obtained his proof by passing 

 ordinary electricity through small pieces of paper 

 soaked in certain chemical solutions, the current 

 being first bridled by making it pass in some part of 

 its course through a piece of wet thread. When 

 solution of sulphate of soda was used, the acid was 

 evolved at the places where the current entered and 

 the alkali where it left, and this equally in each 

 piece of paper when several pieces were arranged in 

 a row. The experiment is as follows : " Three 

 compound pieces of litmus and turmeric paper were 

 moistened in a solution of sulphate of soda, and 

 arranged on a plate of glass, with platinum wires, as 

 in the figure. The wire m is connected with the 



Fig. i. 



prime conductor of the machine, the wire t with the 

 discharging train, and the wires r and s enter into 

 the course of the electrical current by means of the 

 pieces of moistened paper ; they are so bent as to 



