116 M. Fittig on Acetone. 
their principles and disadvantages pointed out by myself in the 
discussion of the Seismic Catalogue of the British Association 
(“Fourth Report on the Facts and Theory of Earthquakes,” 
Trans. Brit. Ass. 1858), it is unnecessary to occupy the English 
reader with the conclusion of the memoir, except to give the 
explanation by the author of his diagram.—R. M. 
EXPLANATION OF THE PLATE. 
. Strong iron bar fixed in the wall. 
. Moveable dise in contact with the arm of lever. 
Pan of fine ashes or brickdust. 
. Small cylinder or prism (viera) resting on 
. Metallic column fixed to the pan, in order to show the direction of the 
primary wave. 
. Two arms of a lever, the longest of which rests on the pendulum B, 
and the shortest acts as detent to a timepiece to prevent it going. 
. Timepiece with spring and balance always wound up, but not going, 
until the earthquake moves the small arm of the lever which acts as 
detent to the balance. 
. Bar fixed in the wall supporting the spiral. 
Wire spiral, marking the vertical motion of the earth-wave. 
. Tube, or guides (regoli), which do not allow the spiral to oscillate hori- 
zontally, but only vertically. 
. Iron bar fixed in the wall, bearing a ring in which 
. The weight which stretches the spiral can move freely. 
. Lever, the small arm of which is lowered by the vertical undulation, 
and the long arm raised; and on account of the ratcheting it cannot 
fall again, and so indicates the height of the vertical wave. 
. Cork cylinder running freely by its own elasticity between two side 
guides (regoli). This cylinder is placed under the weight of the 
spiral, and being lowered by the motion of the ground or vertical 
wave, and remaining where it is driven by the weight, indieates the 
height of the vertical wave. 
Q. Needle of the large pendulum (actual size), with the small cylinder and 
part of the little column which supports it. 
R. Small pendulums on‘a graduated scale, as to length, to note the time of 
the earth-wave. 
ES Oh > 
epee en 
Cmze reh 
ba) 
XV. Chemical Notices from Foreign Journals. By Vi. ATKINSON, 
Ph.D. F.C.S., Teacher of Physical Science in Cheltenham College. 
[Continued from p. 52.] 
Bare * has investigated several processes of decomposition 
of acetone. When sodium is added to acetone, the liquid 
becomes filled with white flakes, and is ultimately converted into 
a lustrous, gelatinous substance, without the disengagement of 
any permanent gas. On subjecting the mass to distillation, a yel- 
lowish viscous oil was obtained which solidified toacrystalline mass. 
This mass, freed by pressure between paper from some adherent 
oil, and crystallized from a small quantity of boiling water, yielded 
* Liebig’s Annalen, April 1859, 
