Scientific Intelligence. 99 
SCIENTIFIC INTELLIGENCE. 
I. CoRRESPONDENCE. 
Correspondence of M. J. Nicklés, dated March, 1853.— Continued. 
E who have experimented on electric light have remarked the 
sae that the current is not established until the two points of charcoal 
ve been brought in contact. It may be made to pass, however, by 
Sidtitg an electric spark froma Leyden jar between the charcoal 
points, an experiment attributed by Sturgeon to Herschell (Annals of 
Electr., viil, 507). In both cases evidently the current is produced by 
causing a passage from one pole to the other of material particles. 
vile M. Masson has since renewed his researches and has rec ei 
the fact, that the vacuum is a conductor of induced electricity. And 
this, fie adds another, that two currents of induction may traverse or 
same wire going in opposite directions without mutual interference. 
as the vacuum was not sufficiently advanced ; but as soon as the succes- 
sive discharges produced an appearance of continued light, the needle 
of the e galvanometer deviated and afforded evidence of an electric cur- 
rent. ‘The deviation increased as the rarefaction was made more per- 
fect, and also as the balls eed the poles were approached. This 
observation was made with the aid of the receiver called the electric 
g. The very long spar ke thus prodaved 1 in the vacuum, consisted o 
two kinds of light quite different in color, form, and position ; one o 
violet color surrounded the negative ball; the other, of a fiery red 4a: 
hered to one side of the positive ball, and ‘extended from the other to the 
negative ball, having bt bs imi laterally a surface of revolution 
ar ound the axis of the 
M. Quet has found fat’ this double light is made up of a series of 
brilliant fajiie entirely separated from one another by dark layers, 
oF thus a species of stratification. The structure was further 
of 
carbon, bichlorid of tin, fluorid of si senita: etc. ; erous brilliant 
layers were thus formed separated by dark layers, forming as it were a 
pile of electric light between the a poles of the receiv 
he nature of the vacuum infl more or less oe ‘iti of os 
two lights i in this phenomenon of dirkSifitation! When the vacuum 
made over fluorid of silicium , the negative light is yellow; when over 
essence of turpentine in glass tubes, the positive pole is covered with 
* This Journal, [2] xv, 114. 
