fz Llectro-Magnetisn. 
the acidulous fluid; by which means the loss of power 
that usually occurs during the filling of the troughs, is pre- 
vented, and the whole power of the n aaatce is greatly aug- 
mented by this concentration. 
These instruments display, in no ordinary degree, a union 
of the philosopher and the mechanist ; for while they are ad- 
eins adapted for research, and have already considerably 
nded undaries of science, they are unrivalled for 
= perfection of their structure, and the consequent facility 
with which they are brought into operation. 
The most interesting discoveries which have recently been 
made in the department of Galvanism, are those which relate to 
_ its connexion with magnetism. ‘That strong electrical dischar- 
ges are capable of affecting the magnetic needle, has long 
been known; but that a magnetic current accompanies the 
electrical (or the calorific) in its passage between the poles 
of the galvanic battery, is a-fact first announced to the world 
by Professor Oersted, of Copenhagen, in the year 1819. To 
the curious results arising from the union of these two 
mysterious agents, po form of the Voltaic apparatus has been 
found more suitable than Hare’s Calorimotor. Ifa wire be 
placed between the poles of this instrument, at the moment of 
its immersion in the acidulous fluid, the wire indicates strong 
magnetic properties, attracting iron filings so greedily, as to 
become tufted all over with them in an instant. And, what is 
rly to be remarked, is, that the effect is not Sonfined 
to iron and those few metals which were supposed to be the 
exclusive residence of the magnetic influence, but extends 
also to wires of every sort of metal.* It is remarkable, 
also, contrary to what is observed in any other effect of 
electricity or galvanism, that the influence of the uniting 
wire passes to the needle, through plates of glass, metal, or 
wood, the disk of an electrophorus, or a stone-ware vessel o 
water ; nor does the sudden interposition of any of these 
bodies destroy or sensibly diminish the effect.”+ (Henry.) 
* And probably to all conducting substances ; si among the substances 
sithexta tried, none but iron or steel retains the magnetic virtue, after the 
con i i i — t is token—nor does iron become perma~ 
nently magnetic when connected directly. with the — poles ; it ap- 
pears to require the interventio on o SS, = or other bad conductor, so 
that it may be magnetised by influence.—Epivor. 
+ Does not this fact favor the idea that the magnetic influence is a mere 
associate of the other powers, existing entirely independent caloric 
or 1 
& 
: 
23 
