36 



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. 



VI. " On the Electrical Discharge in vacua with an Extended 

 Series of the Voltaic Battery." By JOHN P. GASSIOT, Esq., 

 V.P.R.S. Received May 24, 1859. 



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 -j-th of an inch apart. On at- 

 taching the terminals of the battery to the wires in a carbonic acid 



