968 



tbe metallic peroxide being reduced hj the polar particle of oxy- 

 gen, as in other cases it might be by hydrogen itself. The proof 

 that such a chemical relation really exists between the particles of 

 oxygen, would be found in the proportion in which the two sub- 

 stances were reduced. The paper contains an elaborate inquiry on 

 this point in the case of the chloride and of the oxide of silver ; the 

 general result of which is, that these substances are capable of being 

 reduced in various but definite proportions, according as the con- 

 ditions of temperature and mass are varied. AW the terms of this 

 series of ratios have not been determined ; but it is ascertained that 

 the relative loss for the two substances proceeds by intermittent 

 steps, and that the whole action is confined between the limits of 

 the ratio of equality on tlie one hand, and the purely catalytic ac- 

 tion (in which the metaliic oxide would suffer no reduction) on the 

 other : neither of which limits is ever absolutely reached. 



The constant loss of oxygen from the decomposing bodies in 

 equal equivalent proportions is found in the reaction of the peroxide 

 of barium with iodine in the presence of water. In this experiment, 

 the water in the presence of the iodine is reduced just as the per- 

 oxide in the other experiments ; but here the loss is constant, and 

 the change may be represented thus : — 



IH000Ba=IBa4-H0 + 0,. 



In this experiment no oxide of iodine whatever is formed, and the 

 author considers that the formation of the oxygen itself is here the 

 corresponding fact to the formation of the iodous acid, which takes 

 place when iodine acts upon baryta. 



4. " The Calling of the Sea." By Richard Edmonds, Jun. Com- 

 municated by W. J. Henwood, Esq., F.R.S. 



In this communication the author states, that in the neighbour- 

 hood of Penzance there is often heard inland a murmuring or 

 a roaring noise, locally termed "'the calling of the sea," which on 

 some occasions extends to the distance of eight or ten miles ; whereas, 

 at other times, although to a person on the shore the sea may be 

 equally loud, and the state of the weather may appear equally 

 favourable, no sound from the sea can be heard at the tenth part of 

 that distance. From his observations during six years, he concludes, 

 that when the calling of the sea proceeds from a direction different 

 from the wind, or when it occurs during a calm, it is usually fol- 

 lowed within six hours by a wind from the quarter from which it is 

 heard. 



5. •■'On the Structure of the IMembrana Tympani in the Human 

 Ear." By Joseph Toynbee, F.R.S. Sec. &c. 



In this paper the membrana tympani is described as consisting of 

 the following layers, which are quite distinct from each other, both 

 as regards their structure and functions: — 



