290 Proceedings of Philosophical Societies. [ApRit^ 



that horizontal air-tight partitions are made across both tubes at 

 any given intervals of distance, and that openings are made, so 

 that the gases in the corresponding horizontal cells may commu- 

 nicate with each other, in which case each gas, as is well known, 

 would divide itself equally between the two cells. For 30 or 40 

 miles both gases would be found in each cell ; but for the rest 

 of the column, namely, for 1000 miles or upwards, there would 

 be nothing but hydrogen in both cells. 



In the next place, Mr, D. conceives the horizontal partitions 

 to be withdrawn, and considers what change would ensue. 

 There would have been many cells about the summit of the car- 

 bonic acid atmosphere which, when opened for the purpose of 

 communication, would part with half their contents to the colla- 

 teral cells, but half the contents would not be able to fill the. 

 ivhole space of the cell, by reason that the gas was at its mini- 

 mum density before. Hence the gas would be confined to the 

 lower half of the cells, and there would be no carbonic acid in 

 the upper parts. Of course when the partitions were removed, 

 the carbonic acid in each cell would descend till it came in con- 

 tact withi the like gas of the inferior cell. Thus there would be 

 a slight descent of the upper regions of carbonic acid gas. The 

 same also would happen to the hydrogen gas about the summit 

 of its atmosphere, and a still more considerable descent would 

 take place. Mr. D. seems to think there would be no material 

 change in the mixed atmospheres afterwards. Thus the two 

 mixed atmospheres would exhibit equal volumes of each gas in 

 the lowest cells, or at the surface of the earth, though in the 

 whole compound atmosphere the two gases are o^ec^u?! weights. 



All this would take place according to the author's argu- 

 ments were the mixed atmospheres quiescent ; but if the atmo- 

 spheres are hke the earth's atmosphere, in a constant state of 

 commotion, greater or less, still there will be a constant tendency 

 towards that state of equilibrium which is above described. In 

 the conclusion Mr. D. states, that he has a series of observations 

 which support the opinion that the atmosphere at different 

 seasons and elevations exhibits different proportions of its 

 elements in association, which he intends to bring forward on 

 some future occasion. 



March 2. — The Hon. and Rev. Richard Carlton, and Lieut.- 

 Gen. Sir Rufan Shaw Donkin, were admitted Fellows of the 

 Society. 



Two papers, by SirE. Home, Bart. VPRS. were read, on the 

 Coagulation of Blood in an Aneurismal Sac, and also of Blood 

 taken from the Arm, by heated Iron. In the first paper, the 

 author describes the symptoms of the disease in the patient on 

 whom the experiment was tried, during and subsequently to its 

 performance, which was effected by means of a heated acupunc- 

 torial needle ; together with the state and characters of the blood 



