338 THE POPULAR SCIENCE MONTHLY. 



This experience agrees with mine. In the theatre of the Royal 

 Institution, and in the presence of an audience, I once received the 

 discharge of a battery of fifteen Leyden-jars. Unlike Franklin's six 

 men, I did not fall, but, like them, I felt nothing. I was simply ex- 

 tinguished for a sensible interval. 



This may be regarded as an experimental proof that people killed 

 by lightning suffer no pain. 



Sec. 21. Seat of Charge in the Ley den- Jar. Franklin sought to 

 determine how the charge was hidden in the Leyden-jar. He charged 

 with electricity a bottle half-filled with water and coated on the out- 

 side with tin-foil ; dipping the finger of one hand into the water, and 

 touching the outside coating with the other, he received a shock. He 

 was thus led to inquire, Is the electricity in the water ? He poured 

 the water into a second bottle, examined it, and found that it had 

 carried no electricity along with it. 



His conclusion was, that "the electric fire must either have been 

 lost in the decanting or must have remained in the bottle. The latter 

 he found to be true ; for, filling the charged bottle with fresh water, 

 he obtained the shock, and was, therefore, satisfied that the power of 

 giving it resided in the glass itself." ' An account of Franklin's dis- 

 coveries was given by him in a series of letters addressed to Peter 

 Collinson, Esq., F. R.S., from 1747 to 1754. 



So much for history ; but you are to verify the history by repeat- 

 ing Franklin's experiments. Place water in a wide glass vessel ; place 

 a second glass vessel within the first, and fill it to the same height 

 with water. Connect the outer water by a wire with the earth, and 

 the inner water by a wire with the electric machine. One or two 

 turns furnish a sufficient charge. Removing the inner wire, and dip- 

 ping one finger into the outside and the other into the inside water, a 

 smart shock is felt. This was Franklin's first experiment. 



Pass on to the second. Coat a glass jar with tin-foil (not too high) ; 

 fill it to the same height with water, and place it on India-rubber 

 cloth. Charge it by connecting the outside coating with the earth, 

 and the water inside (by means of a stem cemented to the bottom of 

 the jar and a knob) with an electric machine. You obtain a bright 

 spark on discharging. This proves your apparatus to be in good 

 order. 



Recharge. Take hold of the charged jar with the India-rubber, 

 and pour the water into a second similar jar. No sensible charge is 

 imparted to the latter. Pour fresh unelect rifled water into the first 

 jar, and discharge it. The retention of the charge is shown by a 

 brilliant spark. Be careful in these experiments, or you will fail, as I 

 did at first. Note that the edge of the jar out of which the water is 

 poured is to be surrounded by a band of bibulous paper to catch the 

 final drop. 



1 Priestley's " History of Electricity," third edition, p. 149. 



