138 Scientific Intelligence. 
acquired by the plates through the separating force is, on account 
of the great slowness of the motion, vanishingly small in compar- 
ison with the work of that force. is work must consequently 
e equation deduced from this assumption gives again all the 
different laws to which the experiments have conducted. It per- 
for the unit of length, the mass of one gram as the unit of mass, 
and the second as time-unit, it follows that for water of the tem- 
perature of 19° C. this coefficient = -0108, for air = 00183, which 
values almost exactly coincide with those deduced from the exper- 
iments of Poiseuille, Maxwell and O. E. Meyer.— Royal Acad. of 
Vienna, April, 1874; Phil. Mag., xlvii, 465. BOB, 
8. Hifect of Magnetism on an Electric discharge in rarefied 
gvses.—MM. Dr La Rive and Sarasry have in a former memoir 
(Archiv. des Sci., xli, 5) studied the action of.a magnet on a dis- 
of the tube, beyond a long dark interval, and thence to the posi- 
tive electrode streaks wide apart. is appearance is completely 
changed as soon as the magnet is excited. When the negative 
electrode is acted on by the magnet, the negative aureola, which 
or 32m 
trode, presenting an appearance similar to the narrow positive jet 
observed at about 8 or 10 mm. pressure. 
e same effect was obtained with a large bell, in which a cen- 
. . 
placed by a narrow blue jet of vivid splendor, having sometimes 
the appearance of a brilliant blue flame escaping from the positive 
electrode. 
The effect of the magnet on the resistance of the gas was also very 
