On De Luc’s Electric Column. 199 
night, for about ten minutes I did not hear them, but be- 
lieve they were ringing before that time, and stopped 
whilst I was in the room: afterwards the same night they 
made several short pauses, perhaps for the space of a se- 
cond or less. This kind of cessations I frequently noticed 
in the months of September and October: on the 16th of 
the latter they were ringing in the morning, with pauses, 
but in the evening | found they had stopped : from this 
time until the 25th, no ringing ; about nine o’clock on that 
moruing they again began (not having been touched), oc- 
casionally making short pauses as before, and continued 
ringme in this manner until the 16th of November, on 
which day they twice, for very short periods, rang: the 
ringings | suspected might be owing to some accidental 
shake of the apparatus, w vhich occasioned the clapper to be 
released from one of the bells, to which it perhaps was 
attracted. On the 17th, in the evening, they once rang; 
owing again [ thought to a shake. On the isth of No- 
vember, not bh aving heard them ring, I disunited them 
from the columns. I do not wish it to be understood that 
I give the above statement as perfectly certain, for it 1s 
very probabie that the bells might cease and ring at times 
when no observations were made. 
In my paper I have miscalled the ends of the columns, 
so that the experiment of the charged coated jar was ex- 
actly what might have been expected from the known ef- 
fects of the Voltaic Pile. 
On reading Volta’s account of the Galvanic Pile in the 
Piil.sophical Transactions, it appears the idea of forming 
an artificial Electric Eel, by adding a head and tail to the 
ones had occurred to him, which I was not aware of when 
I gave you the description of one in my letter. 
{t is a remarkable circumstance, that alihough these co- 
Jumus. act powerfully on electrometers, and sufficiently ; 
strong to keep in motion a small brass ball, yet with 1500 
series of plates there did not appear to be any production 
of gas or calcination of wire in a glass tube filled with 
water, placed between the two ends of the combined co- 
lumns, —whereas these effects are visible in a Voltaic Pile 
consisting of a series of 25 plates of the size of a half- 
crown. I have some rods fitted up with caps which have 
not any screws, and provided tlie tubes are so filled as to 
cause a sufficient degree of pressure (much is not necessary), 
there does not appear to be any need of screws. Ivory 
caps for this Ppnpess serve very well, perhaps not quite so 
well as brass. Columns of about 450 series of the swall- 
N4 . sized 
