126 Mr. Dallon on Sulphuric Ether. [Feb. 



Elasticity of Ether Vapour, the same in Air and in a Vacuum. 



The same tension or elasticity of ether vapour takes place in 

 air as in a vacuum, just as with the steam of water and other 

 liquids. But this is not true of impure ether, if it be made to 

 pass through water into the air, because by this operation it is 

 improved in quaUty, though greatly diminished in quantity. 



When the temperature of the air was 43°, and barometer 

 29*70, I passed up through water into a graduated tube contain- 

 ing 51 grain measures of air, about three or four grains of 0-73 

 ether. The air was in a few minutes expanded to 74 measures ; 

 and the ether barometer (that is, a barometer with the same kind 

 of ether thrown up into the vacuum) stood at 2U"5 in the same 



temperature ; hence we have ^^ x 51 (^7-^ x 51 j = 74 



nearly ; which accords with the before-mentioned theorem. The 

 tube being afterwards immersed in v.ater of 66° gave 104 mea- 

 «ures of vapourized gas; and in 70° gave 118 measures. It 

 stood for some mouths in water, still retaining a fluctuating 

 volume of gas, according to the changes of barometer and ther- 

 mometer ; and at last the gas was passed through water, and 

 instantly gave the original 61 measures of air. 



The quality of ether may be judged of from passing a small 

 portion of it through water in a graduated tube. Thirty grain 

 measures of the best ether (0-73) passed up a tube of eight 

 inches long filled w ith water lost four or five gr. Thirty grains 

 of another ether, consisting of a mixture of 15 ether (0*735) and 

 15 alcohol (0'8o), when passed in like manner, only gave five 

 measures of fluid ether, swimming on the surface of the water. 



Relation of Ether Vapour to Liquids. 



Gases vapourized by ether may be kept over diy mercury, and 

 transferred through the same v^ithout loss. But they are not 

 kept over water, alcohol, and other liquids, without loss of 

 vapour, though this is variable according to the nature of the 

 fluid and other circumstances. 



Alcohol absorbs ether vapour out of air much faster than 

 water does. I filled two similarly graduated tubes with ether- 

 ized air, and placed ihenr over alcohol and water respectively : 

 they lost vapour asunder: 



Tube over alcohol. Tube over water. 



155 measures. 155 measures. 



116 in 5 minutes. 142 in 10 minutes. 



1 12 in 8 minutes. 138 in 13 minutes. 



104 in 30 minutes. 130 in 30 minutes. 



100 washed. 100 washed. 



