316 Scientific Intelligence. 
with mercury nearly to the 100 mark, and, as the measurement 
is generally made on moist gas, adding a Jayer of water of equal 
depth on each surface. A calculation is then made to determine 
the space which 100 units of volume of dry air at the normal tem- 
perature and pressure would occupy when moist and under the tem- 
perature and pressure shown by the thermometer and barometer 
at the time of the calculation ; and the water meniscus is brought 
carefully to this exact reading on the scale of the instrument. 
The capillary tube above is then closed with wax; or after re 
peated experiments have proved the adjustment correct, it 18 
closed by fusion of the glass. To use the apparatus, the mercury 
is brought to stand at the same height in both legs of the tube, 
and the level of the water meniscus is read off; call it v. Then 
for any volume V of a gas at the same temperature, the volume 
V, dry and at normal pressure is given by the proportion v : 100 
st V2 V.3 whence VV An By surrounding the bulb with 
water it may readily be brought to any required temperature. 
second form of the apparatus, less exact but smaller and more 
portable, is described in the paper.—Ber. Berl. Chem. Ges, XV 
28, Jan., 1884. G. F. B. 
2. On the Influence exerted by the surrounding Gaseous Pega 
EMPEL 
ity. For this purpose the axis of the machine was made vertical, 
passing air-tight through an iron table upon which a glass bell to | 
contain the machine, was secured. ‘The uscless space in this bell 
was filled with paraffin. The quantity of electricity was measured 
by the number of discharges which took place in the air between 
the poles of the machine from a Leyden jar in circuit, for a given 
number of turns of the machine. When the machine was enclosed 
. . 
in hydrogen 850 rotations per minute gave 9 discharges from the 
carbon dioxide, 850 rotations gave 47 discharges, a portion of the 
gas being decomposed into carbon monoxide and ozone. bes 
per minute, On lowering the pressure to half an atmosphere, bce 
jar could not be charged. An attempt to surround the machine — 
Ges., xvii, 145, Feb., 1884 » : 
3. the method employed for cleaning the Liebig Statue — 
On the 6th of November, the marble statue of Liebig, 1D Maxt . 
milian Place, Munich, which had been erected only the previo’™®. 
