174 Ampere and Biot on the coi%nection between 
and hence when we place a magnet in a contrary position, so that 
the poles which point to the poles of the earth are of the same 
name, the currents will be found in the direction of the appa- 
rent motion of the sun. ^ 
6. This law embraces the phenomena of the ordinary action 
of magnets. 
7. It embraces also the phenomena of terrestrial magnetism, 
by supposing electrical currents in planes perpendicular to the 
direction of the dipping-needle, and which move from east to west. 
8. There is no other difference between the poles of a mag- 
net than that one of them is found to the left, and the other to 
the right of the electric currents, which give to steel the mag- 
netic property. 
9. When Volta had proved that the positive and negative 
electricities of the pile attracted and repelled one another, ac- 
cording to the laws of ordinary electricity, he did not demon- 
strate completely the identity of the two fluids put in action by 
the pile and by friction ; but it became a physical truth, per- 
haps, when he shewed that two bodies, one of which was electri- 
fied by metallic contact, and the other by friction acted upon 
one another in every case, as if they had been both electrified 
by the pile, or with the ordinary electrical machine, — the same 
kinds of proof are obtained with respect to the identity of the 
attractions and repulsions of electric currents and magnets. 
Magnetic attractions and repulsions, therefore, ought not to be 
assimilated to those which result from electrical tension, but to 
those which I have observed between two currents.” 
M. Ampere has communicated in his third Memoir, several 
very important results. He has succeeded in directing the unit- 
ing wire (fil conjonctif) by the action (yf the earth. Setting out 
from his method of considering the phenomena presented by the 
uniting wires of magnets, he concludes, that the moveable part of 
the uniting wire ought to form a curved plane, and almost shut, so 
that there remains only between its extremities an interval neces- 
sary to enable it to communicate with the pile, and that then the 
plane of this curve will be carried by the action of the terrestrial 
globe in a direction perpendicular to that of the dipping-needle. 
This conclusion has been fully confirmed by experiment. 
According to the manner in which he suspends this part of 
