LESSONS IN ELECTRICITY. 



331 



"mrple) sparks from the end u of tlio near 

 jodv A B into the end E of the remote 

 body EI-." 



Make clear to your mind tiio origin of 

 thi.s stream of weak red or purple sparks. 

 It i.i obviously dua. to the inductive 

 action of the prime conductor P c upon 

 tlio body A c. The positive electricity 

 of A c being repelled by the prims con- 

 ductor, passed as a stream, of sparks to 



E F. 



" When the prime conductor, Laving 

 received its full charge, came suddenly 

 to discharge, with an explosion, its super- 

 abundant electricity on a large brass ball 

 L, which was made to communicate with 

 lihe earth, it always happened that the 

 electrical fluid, which had been gradually 

 expelled from the body A B and driven into 

 the body E r, did suddenly return from 

 the body E F iuto the body A n, in a 

 strong and bright spark, at the very in- 

 stant that the explosion took place upon 

 the ball L. 



" This I call the electrical returning 

 stroke." 



For the two conductors Lord Mali on 

 then substituted his own body and that 

 of another person, both of them standing 

 upon insulating stools. He continues 

 thus : 



** I placed myself upon an insulating 

 stool E (fig. 56), so as to have my right 

 arm A at the distance of about 20 inches 

 from a large prime conductor ; another 

 person, standing upon another insulating 



es. 



stool K, brought his right hand F within 

 ono- quarter of an inch of my left hand n. 



41 When the prime conductor began to 

 receive its plus charge of electricity, we 

 felt the electrical fluid running out of my 

 hand B into his hand F. 



" V> T hen we separated our hand? B and 

 F a little, the electricity passed between 

 us in small sparks, which sparks increased 

 in sharpness the farther we removed our 

 hands c and F asunder, until we had 

 brought them quite out of a striking dis- 

 tance. The interval* of time between 

 these departing sparks increased also the 

 more the distance between our hands B 

 and Y was increased, as must necessarily 

 be the case. 



"As soon as the prime conductor came 

 suddenly to discharge iU electricity upon 

 the ball L, the superabundant electricity 

 which the other person had received from 

 my body did then r turn from him to me 

 in a sharp spark, which issued from his 

 hand F at the very iiiftaut that the explo- 

 sion of the prime conductor took place 

 upon the ball L. 



44 I still continued upon tho insulating 

 stool E, and I dc&ircd the other person to 

 stand upon the floor. The returning 

 stroke between us was still stronger than 

 it had yet been. The reason of it was 

 this : The other person being no longer 

 insulated, transmitted his superabundant 

 electricity freely into the earth. I conse- 

 quently became still more negative than 

 before. 



" Now, when the returning stroke 



