Chemistry and Physics. 1438 
piece of which a continual current of the gas is conducted, while 
the liquid to be evaporated enters the vertical arm. 
tube provided with a cock be dipped with the cock open 
in ether, the level of the liquid within the tube will sink below 
that outside; and at first the depths to which the interior level 
sinks below the exterior in definite times are as the square roots 
of those times.— Philos. Mag., xlvi, 483. 10, 
6. Prof. Virtart has measured the time required by flint glass to 
change iis magnetic condition, or to rotate the plane of’ polariza- 
tion. A beam of polarized light was passed through the poles of 
a powerful electro-magnet and a glass cylinder interposed, whic 
acted like a cylindrical lens. This cylinder could then be turned 
end over end with any desired velocity. When not magnetized, 
produce the complete effect, 0024" was necessary.—Pogy. An- 
nalen, No. 7, 1873. ec 
_ 7. M. E. Ducnemer addresses a note to the French Academy, 
in which he claims that @ cireular compass needle possesses the 
pieing advantages over the usual for 
Bb, 
— Phat length is equal to this diamete 
2d. 
_ 3d. A more satisfactory means of suspending the magnet when 
1t 1s well mounted and balanced by a plate of agate; it seems 
then to move as if placed in a liquid. : 
_ 4th. An increase in sensibility of the magnet proportional to 
its diameter, 
The possibility of neutralizing the magnetism of the vessel 
by means of a second magnetic circle, changing the position by 
an amount calculated beforehand, and thus permitting the = 
Dr. J. B Roy 
on the electrical phenomena which accompany irritation of the 
leaf of Dionwa muscipula. 
hen the opposite ends of the living leaf of this plant are 
Placed as non-polarizable electrodes and connected with the 
terminals of a Thomson’s galvanometer, a deflection is produced 
Which indicates a current from the proximal to the distal end of 
