DISCOURSE OF W. B. TAYLOR: NOTES. 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, and those relating 

 to 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 effect is not increased ; 

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

 240 feet. 



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

 same length. 



"3. A wire coiled into a helix, gives a more vivid spark than 

 the same wire when uncoiled. 



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

 intense spark than any other arrangement yet tried. 



" 5. The effect is increased, by using a longer and wider ribbon, 

 to an extent not yet determined. The greatest effect has been pro- 

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

 conductor has not been received. 



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

 coiled into a flat spiral, gives no spark, or a very feeble one. 



"7. Large copper handles, soldered to the ends of the coil of 96 

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

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

 half feet of zinc surface. 



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

 with one 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 be 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 current, and 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 of 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. 



