Miscellanies. 199 
wire, of which he made two double helices. One of these helices 
was 0” 44 in length, and had a diameter of 0" 05m ; the other was 
0” 72 metres in length, and 0" 03 in diameter, and was wound on 
a horse shoe. In the interior of the two helices was placed a eylin- 
drical bar of soft iron. With this arrangement, completed as above 
described, Matteucci succeeded without fail in obtaining a bright 
spark. One of the helices wound on a horse shoe sufficed to pro- 
duce the same successful result. 
Matteucci attempted to obtain the electric spark by means of two 
plates of brass, with short wires attached and inserted into mercury. 
But, notwithstanding the employment of every means which could 
insure success, he failed in obtaining any effect except the shock. 
He therefore infers, since the spark is not obtained with a very short 
wire, and on the contrary is easily obtained with the above described 
helices, that the spark is produced where the discharge ceases, in 
which case the current, by induction, adds to the primitive current. 
He has also ascertained, by means of a delicate galvanometer, 
that the current passes from the back to the venter, and that the back 
may be considered the positive pole and the venter the negative. 
The discharge is effected in the same manner by the two organs 
situated on the sides of the torpedo, and the current is produced in 
the same directions when one of the needles of the galvanometer 
touches the ventral part of the Jeft organ and back part of the right, 
or inversely. ‘The deviation in the galvanometer is augmented if the 
two needles of platinum are put in contact with two metallic plates 
placed on the two sides of the fish, instead of a direct application 
of the needles. A discharge can almost invariably be produced by 
forcibly curving the torpedo, making the venter the interior of the 
curve. A removal of the ‘skin of the animal diminishes the devia- 
tion, but does not entirely prevent it. If the outer of the three ner- 
vous cords which proceed from the brain to the electric organs are 
cut, the electric discharge may still continue. It ceases immediately 
on cutting the intermediate one. 
These experiments were tried with thirty six individuals, which M. 
Matteucci obtained during a long residence at Cesenatico.—L’ Insti- 
tut, No. 167. July, 1836. 
14, Fall of Fishes from the Atmosphere in India; by M. Prin- 
sep.—The fact that fishes fall from the atmosphere in the rainy sea- 
son, however incredible it may appear, has been so frequently attested 
