DISCOl BSE OF W. B. TAYLOR: — XOTES. 395 



" Extract from the proceedings of the stated meeting of the American 

 Philosophical Society, January 16, 1835. 



"The following facts in reference to the spark, shock, &c. from 

 a galvanic battery, when the poles are united by a long conductor, 

 were communicated by Professor Joseph Henry, ami those relating 

 tn the spark were illustrated experimentally: 



"1. A long wire gives a more intense spark than a short one. 

 There is, however, a length beyond which the eifect is not increased; 

 a wire of 120 feel gave about the same intensity of spark as one of 

 240 feet. 



"'_'. A thick wire gives a larger spark than a smaller one of the 

 same length. 



"'■). A wire coiled into a helix, gives a more viviil spark than 

 the same wire when uncoiled. 



"4. A ribbon of copper, coiled into a Hat spiral, gives a more 

 intense spark than any other arrangement yet tried. 



''•"). The effect is increased, by using a longer and wider ribl , 



tn an extent not yet determined. The greatest effect has Keen pro- 

 duced by a coil 96 feet long, ami weighing 15 pounds; a larger 

 conductor has nut been received. 



"(>. A ribbon of copper, first doubled into two strands, and then 

 coiled into a fiat spiral, uives no spark, or a very feeble one. 



"7. Large copper handles, soldered to the ends of the coil of '•"> 

 feet, and these both grasped, one by each hand, a shock is felt at 

 tlie elbows, when the contact is broken in a battery with one ami a 

 half feet of zinc surface. 



"8. A shock is also felt when the copper of the battery is grasped 

 with ime hand, and one of the handles with the other; the inten- 

 sity however is not as great as in the last case. This method of 



receiving the shock may lie called the direct method, the other the 



lateral one. 



"9. The decomposition of a liquid is effected by the use of the 

 coil from a single pair, by intermitting the cm-rent, ami introducing 

 a pair of decomposing wires. 



"10. A mixture of' oxygen and hydrogen is also exploded by 

 using the coil, and breaking the contact, in a bladder containing the 

 mixture. 



"11. The property <>f producing an intense spark is induced, on 

 a short wire, by introducing, at any point of a compound galvanic 

 current, a large flat spiral. 



"12. A spark is produced even when the plates of a single bat- 

 tery are separated by a foot or more of' diluted acid. 



