226 WATER AND OIL. 



cases, hoping that beat and pressure might compel the hidies to resign their 

 posts, and afford them an opportunity of hearing the Lectures, or seeing the 

 speakers — but in this they formed an erroneous calculation, the ladies of Edin- 

 burgh possessing the love of science too ardently to be driven away by heat and 

 pressure. 



For several previous days, the roads in every direction were thronged with 

 vehicles bearing company of both sexes to the Scotch metropolis. The arrange- 

 ments made for their reception were admirable : all the public institutions, 

 libraries, exhibitions, and news-rooms were thrown open ; invitations in blank 

 were left by many for those who were unprovided with letters of introduction ; 

 and very few of the members were permitted to go into hired lodgings. At 

 York, Newcastle, and other towns on the line of road, from every quarter, the 

 hotels were so crowded that it was impossible to get beds ; and vast numbers 

 were unable to proceed, for want of conveyances, until the meetmg was over ! 



On the first day, (Monday,) at five o'clock, there was a dinner in the Hope- 

 town Rooms, Professor Sedgwick in the Chair, at which 350 members 

 attended. The health of M. Arago, the Astronomer Royal of France, who was 

 present, was proposed, and the toast received with the utmost enthusiasm. M. 

 Arago returned thanks, and dwelt at some length on the advantages that must 

 result from the union of the minds of Europe ; he regarded it as the pledge of 

 the peace of the world, because intellectual supremacy daily acquires more 

 direct power over the affairs of nations, and when the intellectual rulers are 

 banded in friendship, the nations subject to their influence cannot be forced 

 into hostility. These noble sentiments produced considerable impression. M. 

 Arago possesses great physical advantages : in figure he resembles theFarnese 

 Hercules ; his voice is, at the same time, powerful and melodious — his action 

 rounded and graceful. 



The following are a few of the distinguished strangers who w^vq present at 

 this Association : — Professor Arago ; Le Chev. Gregoire Berardi ; F. G. Von 

 Druffel ; M. le Baron Ende ; Monsieur Gerard ; Dr. Vlastos ; Dr. Bernhard 

 Erbkam, from Berlin ; Professor Henslow ; Professor Moll, of Utrecht ; 

 Professor Ullman, of Berlin. 



Sir David Brewster, D. C L., F. R. S. ; Francis Baily, V. P. R. S. j H. S. 

 Boase, M. D.. M. G. S. C. ; Rev. W. Buckland, D. D., Professor V. P. G. S., 

 F. R. S. ; John Dalten, D. C. L., F. R. S. ; C. Daubeny, M. D., F. R. S. ; G. B. 

 Greenhough, P. G. S. ; W. Huton, F. G. S. ; Luke Howard, F. R. S. ; Rev. J. S. 

 Henslow, M. A., F. L. S. and G. S., and Professor ; AV. J. Hooker, Professor ; 

 Charles Lyell, M. A., F. R. S., L. S. and G. 8. ; Rev. Dr. Lardner, LL. D., 

 F. R. S. ; Capt. Maconochie, F. G. S. ; Sir G. S. Mackenzie ; R. J. Murchison, 

 P. R. S., V. P. G. S. ; Rev. B. Powell, M. A., F. R. S. ; Col. Silvertop, F. G. S, j 

 Professor A. Sedgwick, M. A., F, R. S. and G. S. ; D. L. C. Treviranus, of 

 Bonn ; A. Van der Toorn ; John Taylor, F. R. S., Treas. G. S. ; Professor 

 Edward Turner, M. D., F. R. SS., L. and E. ; H. T. M. Witham, F. G. S. ; Rev. 

 W. Whewell, M. A., F. R. and G. SS. ; James Yates, M. A., F.L. and G.S. 



Water and Oil. — If a glass tumbler, containing equal parts of water and oil, in 

 such quantity as to occupy two-thirds of it, be suspended by a cord, and swung 

 backwards and forwards, the oil will remain perfectly smooth and undisturbed, 

 whilst the water below is in violent commotion. If the oil be poured out, and its 

 place supplied with water, the fluid will remain perfectly tranquil throughout the 

 whole vessel, though the same motion be given to it as before. If spirit of wine be 

 substituted for water, the oil, being the heavier fluid, becomes agitated, while the 

 spirit remains at rest. This circumstance has been supposed to arise from a re- 

 pulsive power, subsisting between the particles of oil and water, or from the different 

 gravities of the two fluids ; but is now found to proceed, solely, from the different 

 velocities necessarily impressed on the upper and lower parts, for one homogeneous 

 fluid, water alone, undergoes the very same motion at the bottom, which is rendered 

 sensible by impregnating the lower part of the water with some colouring material, 

 or by dropping a coloured powder, as yellow ochre, into the water during the 

 vibration. 



