S^* Mr. Howldy's Remarks on Mr. Sturgeon's Paper. 



becomes so attenuated in its passage to the jar, as to be in- 

 capable of affecting the organs of sight. This circumstance 

 very frequently occurs when the charge is directed over an 

 imperfect conducting surface, if the distance be greater than 

 that over which the charge can strilce in the form of a spark, 

 or with explosion. 



If Mr. Sturgeon is acquainted with this fact, he has on 

 the present occasion inadvertently employed the expression, 

 striking distance. — The electric fluid by expanding or diffusing 

 itself over an imperfect conducting surface of some extent, 

 often passes as invisibly as it does when it pervades a metallic 

 conductoi'. In the next clause to that which I have been 

 considering, Mr. S. says : " not happening to be successful 

 when attempting to repeat the experiment, according to Mr. 

 H.'s directions, I have been induced to suggest to that gentle- 

 man the necessity of his repeating the experiment, under the 

 following ch'cumstances." 



Now, it Mr. Sturgeon found the experiment to be either 

 impracticable, or to be more difficult to be performed success- 

 fully by my method than by that with the water tube, he 

 ought, I submit, for his own credit and the satisfaction of his 

 readers, to have pointed out clearly and demonstratively in 

 what the difiiculty or impracticability consisted. The state- 

 ment of facts, and the observations which I have made relating 

 to the subject in discussion, will relieve me from the necessity 

 of repeating the experiment under the circumstances Mr. S. 

 has suggested, especially as I perfectly agree with him that 

 " there would recur different results." Mr. S. seems to have 

 misunderstood a part of my statement concerning the wooden 

 point or peg, and has asserted that the celebrated electricians 

 Dr. Watson and Mr. Wilson " used it in that shape more 

 than fifty years ago." I must observe, however, that Priestley, 

 in his History of Electricity, (^to, fourth edit. 1775,) has given 

 an account of Dr. Watson's experiments ; but he has not stated 

 that Dr. Watson used a wooden point in any of them. And 

 as to Mr. Wilson, I have his own account of the experiments 

 he made, under the patronage of His late Majesty, in the large 

 room at the Pantheon ; and I do not find that in any of his 

 various experiments he employed a wooden point : and the 

 manner in which he inflamed gunpowder shall be told in his 

 own words : " Upon a staff of baked wood a stem of brass 

 was fixed, which terminated in an iron jwijit at the top. This 

 point was put into the end of a small tube of Indian paper, 

 made somewhat in the form of a cartridge, about one inch 

 and a quarter long, and about two-tenths of an inch in dia- 

 meter. When this cartridge was filled with common gun- 

 powder 



