182 Mr. Snow Harris 07i Defending Ships J'rom Lightiiing, 



that chemical decompositions are easily performed by it, and 

 every other class of electrical phaenomena, exhibited with a 

 sufficiently large apparatus, as decidedly as by the primitive 

 discharge itself." Now the plain truth is, there is no such 

 effect as he describes produced by a passing charge of elec- 

 tricity. It is altogether a fallacy» arising out of his being 

 very ill informed on the subject, and from his having mis- 

 taken the common result of the residual accumulation for a 

 lateral explosion, as 1 think I have fully shown ; Cavallo and 

 the old writers have taken great pains to guard the ifiexpe- 

 rienced manipulator against this source of error. 



In short, if Mr. Sturgeon will look at Cavallo, Priestley 

 and other writers of above half a century since, he will find 

 his theoretical and experimental researches very perfectly 

 imitatcd'y by a most extraordinary coincidence, the experi- 

 ments are virtually the same ; the deductions, however, from 

 them are widely different. With such careless manipulation, 

 and such a great lack of knowledge of his subject, it is not sur- 

 prising that Mr. Sturgeon should deem others ignorant of it. 



These experiments were not the only experiments which 

 were made matters of discussion by the Board. Thus, to 

 show that in the case of the sliding masts being entirely, or 

 partially lowered, that part of the conductor below the caps 

 would be the same in respect of the discharge as it it did not 

 exist, strips of gold-leaf were laid on paper in the same re- 

 lative positions as the conductors would assume on the masts, 

 and powerful discharges sufficient to disperse the gold passed 

 over them. 



These strips were affected in certain jiarts only, showing 

 how completely the discharge was confined to such parts, 

 and the total absence of all lateral explosion. 



Experiments on the expansive effects of electricity on 

 bodies, the fusion and heating of metals, &c. &c. were also 

 entered upon. In short, the series was as complete as could 

 well be desired. The experiments were all original, or other- 

 wise new, of their kind, and many of them embraced points 

 not before considered ; such experiments had for the most 

 part never been tried before; and they were considered by 

 Dr. WoUaston and others who investigated them to be of 

 great interest, and to have an important bearing on the ques- 

 tion of lightning conductors in ships. 



I suppose it will be admitted that Dr. Wollaston had at 

 least as clear a comprehension of this subject as Mr. Stur- 

 geon, and was just as likely to have detected the "necromancy" 

 to which Mr. Sturgeon alludes, had such existed. 



This explanation of the practical nature of the experiments, 



