Messrs. J. B. Hanriay and J. Hogarth. [Nov. 20, 



equalities at Kew, Utrecht, and Toronto are very like the mean of the 

 three and like each other. 



(5.) Of these the Kew inequalities are most like the mean, and 

 the Toronto least so. 



(6.) The declination-ranges at Kew and Prague exhibit certain 

 common periods which we may regard as the same, or very nearly the 

 same, as the meteorological periods above indicated. 



(7.) Similar magnetic phases appear to occur at Kew about one 

 day before they occur at Prague. 



(8.) Correcting for this difference of phase, the individual inequali- 

 ties at Kew and Prague are very like the mean of the two, and like 

 each other. 



(9.) There is also a less striking likeness between the various mag- 

 netical and the corresponding meteorological inequalities. 



(10.) Provisional sun-spot records appear to show certain solar 

 inequalities very like the magnetic and meteorological inequalities in 

 point of period. 



22. In conclusion we would express our hope that steps will be 

 taken to ascertain what information exists in the world available for 

 these researches, and also to bring such information together for the 

 purpose of a further and more complete discussion of the laws now 

 indicated. 



VI. " On the Solubility of Solids in Gases." By. J. B. HANNAY, 

 F.R.S.E., F.C.S., and James Hogarth. Communicated by 

 Professor G. G. Stokes, D.C.L., LL.D., Sec. R.S. Received 

 October 8, 1879. 



(Preliminary Notice.) 



This investigation was undertaken in the hope that, by an examina- 

 tion of the conditions of liquid matter up to the "critical" point, 

 sufficient knowledge might be gained to enable us to determine under 

 what particular conditions liquids are dynamically comparable, in order 

 that the microrheometrical method* (which the Royal Society has 

 done one of us the honour of publishing in the " Philosophical 

 Transactions") might be applied to determine their molecular mass 

 and energy relations. It seemed that as the laws relating to gases 

 and liquids merge at what was called by Baron Cagniard de la Tourf 

 " Petat particulier," and by Dr. Andrews^: the "critical point," an 

 examination of matter up to the limit of the liquid state would be 



* " On the Microrheometer," " Phil. Trans.," rol. clxx, p. 275. 



f " Ann. Cbim.," Series 2ine, xxi, p. 127 ; xvii, p. 410. 



% " Bakerian Lecture, " Phil, Trans. Roy. Soc.," 1869, p. 588. 



