146 = Electro-Magnetic and Galvanic Experimenis. 
A wire was made to circulate with great rapidity, by 
means of two wheels about which it passed like a band. 
The wheels being metallic, and severally connected with 
the different poles of a colorimotor, it was found that the 
motion neither accelerated nor retarded the galvanic influ- 
ence—and it made no difference whether the needle was 
placed near the portion of the wire which moved from the 
positive pole to the negative, or the portion which moved 
in the opposite direction. 
If a jet of mercury, in communication with one pole of a 
very large calorimotor, is made to fall on the poles ofa horse- 
shoe magnet communicating with the other, the metallic 
stream will be curved outwards or inwards, accordingly as 
one or the other side of the magnet may be exposed to the 
jet—or as the pole communicating with the mercury may 
be positive or negative. When the jet of mercury is made 
to fall just within the interstice formed by a series of horse- 
shoe magnets, mounted together in the usual way, the stream 
will be bent in the direction of the interstice, and inwards 
or outwards. accordingly as the sides of the magnet, or the 
communication with the galvanic poles, may be exchanged. 
This result is analogous to those obtained by Messrs. Bar- 
low and Marsh, with wires, or wheels. 
It is well known that a galvanic pair, which will, on im- 
mersion in an acid, intensely ignite a wire, connecting the 
zinc and copper surfaces, will cease to do so after the acid 
has acted on the pair for some moments—and that ignition 
cannot be reproduced by the same apparatus, without a 
temporary removal from the exciting fluid. 
I have ascertained that this recovery of igniting power 
does not take place—if, during the removal from the acid, 
the galvanic surfaces be surrounded either by hydrogen 
gas, nitric oxide gas, or carbonic acid gas. When sur- 
rounded by chlorine, or by oxygen gas, the surfaces regain 
their igniting power, in nearly the same time as when ex- 
posed to the air. 
The magnetic needle is, nevertheless, much more pow- 
erfully affected by the galvanic cireuit, when the plates 
have been allowed repose, whether it take place in the air 
or in any of the gases above mentioned. 
I have not yet had time, agreeably to my intention, to 
examine the effect of other gases, or of a vacuum. 
