On the Electrical Discharge of the Voltaic Battery. 59 
long was substituted, through which the sound of the fork was again 
heard faintly for four seconds. 
The inference from the two series of experiments above detailed is, 
that neither the variation of the plane existing in the chain of 
ossicles, nor the presence of the articulations, is sufficient to prevent 
the progress of sonorous undulations through this chain to the 
vestibule. 
The experiments and observations detailed above lead to the 
following conclusions :— 
1. That the commonly received opinion in favour of the sonorous 
undulations passing to the vestibule through the chain of ossicles is 
correct. 
2. That the stapes, when disconnected from the incus, can still 
conduct sonorous undulations to the vestibule from the air. 
3. So far as our present experience extends, it appears that in the 
human ear sound always travels to the labyrinth through two media, 
viz. through the air in the tympanic cavity to the cochlea, and through 
one or more of the ossicles to the vestibule. 
“On the Electrical Discharge in vacuo with an extended Series of 
the Voltaic Battery.’ By John P. Gassiot, Esq., V.P.R.S. 
In a recent communication, since ordered for publication in the 
Philosophical Transactions, I described some experiments on the 
electrical discharge in a vacuum obtained by the absorption of 
carbonic acid with caustic potassa, and I showed that, when the dis- 
charge from an induction coil was passed through such a vacuum, the 
stratifications became altered in character and appearance as the 
potassa was more or less heated. I have also in a former paper 
(Phil. Trans. 1858, p. 1) shown that the stratified discharge can 
be obtained from the electrical machine. 
A description of an extended series of a water-battery was com- 
municated by me as far back as December 1843 (Phil. Trans. 1844, 
p- 39). This battery consists of 3520 insulated cells: some years 
had elapsed since it was last charged, and I found the zincs were 
very much oxidated; on again charging it with rain-water, I ascer- 
tained that there was sufficient tension to give a constant succession 
of minute sparks between two copper discs attached to the terminals 
of the battery, and placed about 1th of an inch apart. On at- 
taching the terminals of the battery to the wires in a carbonic acid 
vacuum-tube inserted about 2 inches apart, I obtained a stratified 
discharge similar to that from an induction coil. 
The experiment was repeated with 400 series of Grove’s nitric 
acid battery. In this case distinct sparks between two copper discs 
were obtained, and the luminous layers were shown in a peculiar and 
striking manner, thus proving that the induction coil is not necessary 
for the production of the strize, as in most of the experiments the 
only interruption of the battery circuit was through the vacuum- 
tube. 
I had another tube prepared, substituting for metallic points balls 
of gas-carbon. At first the stratified discharge was obtained as before, 
