ACCUMULATORS. 81 



size ; and connection with any part of either coating 

 affects the whole of that coating. 



DISCHARGE THROUGH A BOOK. The discharge 

 from a Leyden jar or battery, passed through a card or 

 a thin book, leaves a puncture, with a burr projecting 

 from each surface. 



Fig. 23 Discharge Through a Book. 



To perform this experiment successfully, let one 

 knob of the discharger be placed in contact with the 

 outer coating, and the other in contact with the book ; 

 and let the book, held by its edge, with the knob 

 against it, be brought quickly into contact with the 

 knob of the jar, and the discharge will take place as 

 shown in Fig. 23. 



