264 
DR. DAVY’S ACCOUNT OF SOME EXPERIMENTS 
contact wire was made the upper, the effect on the deviation of the needle was 
identical with a change of the plates. 
I have found the same uniformity of result in the polarity imparted by the 
torpedo to a needle in the spiral wire ; the extremity of it, nearest the under 
surface in the circle, has always acquired southern polarity, and the other ex¬ 
tremity, of course, northern. 
By connecting the spiral with the multiplier, and charging the former with 
as many small needles as it could hold, namely, eight, I ascertained that a 
single discharge of the electricity of an active fish moved the needle in the 
multiplier powerfully, and converted all the needles into magnets; and each 
of them I believe was as strong as if one only had been used. 
Using two spirals charged with needles, one connected with one end of the 
multiplier, and the other with the other end, the effects of the discharge were 
similar to the preceding, both on the needle of the multiplier and on the 
needles in the spirals. In two instances, the needles in the spiral connected 
with the upper surface, were most powerfully magnetised; and in one instance, 
the effect was greatest on the needles in the lower spiral. In this last instance 
nine needles were acted on in the under spiral, and six in the upper; the fish 
which produced the effect, with one exception, was the smallest that I had 
ever used. 
The preceding are the principal experiments which I have made on the 
electricity of the torpedo, using perfect conductors to convey it. I have, be¬ 
sides, instituted some in which the communication by perfect conductors was 
interrupted by imperfect ones ; a few of these I shall briefly notice. 
When I have held the contact-wires in the palm of each hand, wetted with 
salt water, and have touched with the fore-fingers the upper and under sur¬ 
face of a torpedo, I have felt its shocks distinctly; but in no instance when 
the multiplier has been connected with the wires, has it been affected; and 
when the spirals have been connected with them, I have once only seen the 
needles in them converted into magnets. This effect accompanied a very 
smart shock from a young active fish, about six inches long, just taken. 
When the touching ends of the contact-wires have been covered with 
leather soaked in salt water, or with cotton thread, all the effects of the fish, 
as might be expected, were witnessed, as if these imperfect conductors had 
