163 Accouni cf some "Electrical Experiments. 



simple metals ; for a cylinder of pure silver was cracked at the 

 fourth explosion, whilst a similar cylinder of sterling silver re- 

 sisted eleven explosions without injury; and when any soldered 

 metal was employed, the solder was found less susceptible of in- 

 jury than the metal soldered. From these circumstances M. 

 De Nelis is disposed to ascribe the effects produced, rather to 

 the attraction of the electric fluid for the metals, than to the ex- 

 pansion which its rapid passage through imperfect conductors 

 so invariably produces. 



Anxious to ascertain the extent to wh.ich these effects might 

 be carried, he employed a cylinder of iron, 18 lines diameter* 

 and 27 lines high, having a hole drilled in its axis of one line 

 and a half diameter and IS lines deep; and it was torn open 

 by 70 discharges of a battery of 100 feet of coating. The re- 

 sults of former experimiCnts having rendered it probable that 

 this large cylinder had yielded to a ]ower power than would 

 have been requisite had the iron been perfect, another cylinder 

 of the same size was made with great care, and 70 explosiojis 

 produced no effect upon it. The interior of this cylinder was 

 then filled with olive oil instead of water : in 30 explosions the 

 bottom was perforated, though nine lines thick ; the lateral ex- 

 pansion was very inconsiderable. M. De Nelis supposes that 

 in these experiments the leaden wire is minutely divided, and 

 combines with the oil or water and with the electric fluid tu 

 form a gaseous product, which exerts a powerful action on the 

 metal cylinder by which it i:5 surrounded. By this he appears 

 not merely to express an expansive effect, but a peculiar attrac- 

 tion which he conceives to exist between the electric fluid and 

 other bodies, and to which he applies the general term molecular 

 attraction. This peculiar action he thinks decisively evinced 

 by the last experiment ; in which the bottom of the cylinder, a 

 thickness of nine lines of excellent iron, was perforated, whilst 

 the sides remained nearly without iujury. By an extension of 

 this experiment still more reniarkable effects were produced ; it 

 was imagined that by increasing the thickness of the cylinder. 

 the lateral expansion would be entirely prevented, and the ac- 

 tion of the charge be confined to its molecular attraction oa 

 the bottom of the cyliiider. An iron cylinder of 28 lines diame- 

 ter was drilled to within five lines of the bottom, and a cylinder 

 of pure silver of the same size was procured ; they were sub- 

 mitted in succession to the action of the battery. 200 explo- 

 sions perforated the bottom of the iron cylinder, and produced 

 an excavation of three lines diameter. With the silver cylinder 

 20 explosions occasioned an expansion at bottom, which con- 



* One inch and a half tDgliih ; the line being one-twelfth of an inch 

 jicaiJy. 



tinued 



