Chemistry and Physics. 
temperature, the wire arrives at a 
nary temperature, pie then partial- 
ly untwisted, loses eating so 
much the less of its sania, the far- 
ther it has been untwisted. Upon 
cooling, its torsion is less than before 
if the detorsion has been slight, but 
greater if this has been considerable. 
. A wire twisted at a higher 
temperate, loses torsion on cool- 
U a second heating, it 
Rot loses, and upon a second cool- 
ing first regains a portion of its loss. 
hen the wire is vibrated previous 
to the first ee it immediately 
gains in torsion. 
From this i comparison it 
the pheno 
even in the d details 
cannot justly infer from it, that the 
torsi 
a of magnetism and those 
Fhe author remarks that this 
435 
— the bar arrives at a 
onstant state, in which to every 
hail — corresponds a definite 
of the bar, which dimin- 
dinary temperature, and then par- 
tially demagnetized, loses by heat- 
ing so much the less of its magnet- 
ism the farther = = been demag- 
netized. , its magnetism 
is less than below: ms the demag- 
netization has been slight, but 
greater when this has been consid- 
erable, 
19. Ab tiger atc ih As 
temperature loses magne on 
the first eos it immediately 
gains in magne 
t will be seen that there is an alia between 
good 
on. This is not proved by experi inc moreover as he proposes to 
show in an 
other memoir, similar relations are found in the case of other 
rare age displacements, as for example, in flexion—Pogg. Ann., evi, 
the densities of vapors at high temperatures —H. Sarnte CLarre 
oe 
tienes and Troost 
f 
0 
which they enclosed siiscenaivel vapor of i 
‘hi his manner, ci ratio of the a pabition of 
ensit 
ing been previously accurately 
were as follows 
on ave perce their te et on the densities 
scribed, but Pre ti) 
° °C. ) for 
were nish tpl instead of glass, 
ne and the v 
of the vapor of iodine hav- 
oer By this a deter- 
mination of the temperature becomes unnecessary, T 
Sulpbur, at the temperature of 860° has a vapor catty of 2°2, and 
this density does not change as the temperature rises, being the same at 
1040° as determined by more than twelve experiments. We may there- 
