376 Mr. Herinessy mtibgi^ffdnnexi&n between the Boiation of 



The bleaching action which the substance contained in elec- 

 trolytical oxygen produces when dry on litmus paper, is a fact 

 which of" itself indicates that it must be a peroxide. It is well 

 known that chlorine does not possess that property, but only 

 such combinations of oxygen, as give up this element with 

 great ease, as for instance hypochlorous acid. 



I cannot conclude this notice without expressing the obliga- 

 tion I am under to Professors Liebig and Buff for their kmd^ 

 irection and assistance during these experiments. 



I 



LIX. Some Researches upon the Connexion between the Ro- 

 tation of' the Earth and the Geological Chaftges qfiitSr&ti^afa,, 

 By Henry Hennessy, Esq.* > jaixs vi'.nuwwi^iVOuMVm'v 

 T is now generally acknowledged tli'at the agency of modern ' 

 causes in producing geological changes on the surface of 

 the earth is of no inconsiderable importance. Although the? 

 amount of matter which in the course of centuries may change 

 its position on the surface of the earth, by the action of ele-^' 

 vating and degrading forces, is thus locally important to the 

 earth's surface, it must appear insignificant when compared 

 with the mass of the entire globe. From this circumstancej - 

 it may at first appear futile to examine how the rotation 6f» 

 the earth could be affected by the mechanical action of the 

 changes in position of such comparatively minute portions of 

 its mass. It may be said that observation has not yet disclosed 

 any irregularity in the period of the earth's rotation, but this 

 could occur when the causes producing such an irregularity 

 would be counteracted by others having a contrary tendency^ 

 It is here proposed to examine how certain changes of po*i 

 sition, with respect to the earth's centre of masses on its sur- 

 face, would affect its rotation. Let « represent the earth's 

 angular velocity of rotation, M its mass, v the sum of the ve- 

 locities impressed on it, by which both its rotation on its axis 

 and its translation through space are produced, h a perpen- 

 dicular from its centre to a plane passing through the centre 

 of the impressed forces, and I j|i^;a§?i^Ai <?ltjn?5feii9/jta. 

 whole mass. 1 hen . „ . ..aot^aagovjisi? ai ybod ailj 



ii JaJ .aaJiiriib'io-oa ^ij-. fiii^ ah jnelaai pdJ^iinolanB-ttai 



.From this well-known formula, it is evident that any change 

 in the value of 1 must produce a corresponding change in the 

 value of (w. If fl represent the arc through which a point on 

 the surface of the earth is carried during a certain time /, and 

 if t' represent t when w becomes w' by a change of I into 1', 

 ^ftth aril "lo lojo Hoq oh raoit a;wii>}eii) 



* Communicated by the Author. 



