158 ME. GASSIOT ON THE STEATIEICATIOXS IN ELECTEICAL DISCHAEOES, 
which conducts, the stratifications in each tube become cleai' and distinct, the dai'k dis- 
charges becoming as visible as if the circuit vrith the coil had been completed by a smgle 
tube. 
If the tube which conducts is replaced by one such as I have described in this Note, 
it will be found that the discharges in the two tubes attached to the coil are recipro- 
cating, while in that with which they are connected no luminous discharge will be per- 
ceptible, until heat is applied to the caustic potassa, when in a short time flashes of light 
will be observed, and then the cloud-like stratifications, the discharge in the two tubes 
at the same time being no longer reciprocating, but continuous. 
If a vacuum-tube is connected by flexible wires to the terminals of an induction coil, 
the tube can, when held by the hand, be moved to and fro with a rapid motion , if while 
in this state the discharges are made they will appear separated, fonning in darkness a 
very brilliant fan-like figure. In my former communication* I have shown that, what- 
ever might be the length of a luminous stratified discharge in a vacuum-tube, “the 
full intensity of the discharge is visible at a single contact, exhibiting 80 to 100 strati- 
fications (36).” When a single disruption of the primary chcuit is made in the manner I 
have described (30), while the vacuum tube is moved to and fro with rapidity, or if by 
an apparatus which I have had constructed, the tube is rotated in a plane, only a single 
discharge showing stratifications will be visible ; the discharge takes place in that part 
of the circle in which the tube happens to be situated, at the instant of the disruption 
of the primary circuit ; but when the vibrating contact breaker of the coil is substituted 
for the single disruption (30), the motion of the tube gives it the appearance of illuminated 
spokes in a rotating wheel, the discharges being separated according to the velocity of 
the rotation. 
I venture to offer this experiment as an evidence that the stratified discharge in vacuo 
is entirely due to a single disruption of the primary circuit. 
Jan. 10, 1859. 
Note. — Received February 17, read March 3, 1859. 
Since my communication to the Royal Society (read January lo) I hate repeated the 
experiment of Mr. Grove, wherein by an interruption of the secondary circuit through 
air the stratifications of the electrical discharge in a vacuum-tube are destioted, the 
results I have obtained, and which I now proceed to describe, tend to confirm me in the 
opinion I originally ventured to offer, that the stratifications arise from the effect due 
to pulsation, or impulses of a force acting on highly attenuated matter, and are not 
due to a conflict of two currents in the manner explained by Mr. Grove, which his 
experiment of simply making an interruption of the secondary circuit ‘f’ has led him to 
suggest ; these results also show that the varied form observable in the stratifications 
mainly depend on the greater or less density of the matter remaming in the tube. 
* Philosophical Transactions, 1858, Part I. t Philosophical Magazine, 1858, p. IS. 
