Rev. J^ B. Emmett on an Electriaal Phcenomenon. 171 



length, which was kqit close to the floor of the room by 

 weights, at the distance of 10 or 15 feet from each other. As 

 before, the whole length was illuminated ; and the streams of 

 electric light were as long, but not quite so brilliant, as when 

 the shorter wires were used. 



Being fully satisfied as to the fact, I requested a number of 

 my scientific friends to examine the phaenomenon : in their 

 presence, the following facts were ascertained. TJie cushion be- 

 ing insulated by a glass pillar two feet long, the wire attached 

 thereto is illuminated at every spark which passes round the 

 globe, when in contact with the floor of the room : the light 

 is always white : it was extended along the whole of any length 

 of fine silver wire which we could make use of, and which we 

 used to the extent of about 80 feet. If a conducting substance 

 be brought within about | an inch of any part of the wire, 

 whenever the wire is illuminated a very pungent and dense 

 spark is obtained : if the wire be connected with the gold-leaf 

 electrometer, at every illumination of the wire a dense spark 

 passes from the leaves to the tin foil ; the leaves are scarcely 

 separated, nor are they violently agitated ; a very trivial undu- 

 lation alone being observed, although the spark emitted was 

 at the least ^ an inch long. Next, the wire was insulated 

 by being attached to glass rods, placed at sufficient intervals 

 from each other. The wire was always negatively electrified ; 

 and since a star of light appeared at the end of the wire, we 

 were certain that the insulation was good ; the wire being about 

 80 feet long: the illumination took place, as before, at every 

 spark which flew round the globe. On presenting the finger 

 towards any part of the wire, a stream of electric light was 

 seen between them (the wire being highly negative) ; but, as 

 before, at the moment of a spark, a very dense spark passed 

 between the wire and the finger : the effect upon the electro- 

 meter could not be so well observed as when the uninsulated 

 wire was used ; for on bringing it sufficiently near to the wire, 

 the leaves were permanently open and considerably agitated ; 

 yet at every spark, one passed from one of the leaves to the 

 tinfoil without injuring or agitating the leaf. 



I do not hazard a conjecture respecting the cause of this 

 phaenomenon : however, the electricity seems to be in the same 

 condition with that observed by Dr.Priestley, which he deno- 

 minated the lateral explosion. 



The machine with which these experiments were made, con- 

 sists of a globe of what the workmen term black or common 

 bottle glass; its diameter is about 18 inches: the conductor is 

 3 feet lung, and 6 inches in diameter: the sj)ark measures 

 about 1 2 iiiches, when the machine is pretty well excited ; 



Z 2 when 



