19B ! . Dr. Bostock on the Boiling Foiht of Ether. . [M arch, 



Remarks. 



The mean temperature of the year just elapsed very nearly 

 corresponds -svith that of 1819, and the amount of rain, which is 

 about six inches less than in the preceding year, is on a similar 

 par with that for 1822. Upwards of 2U inches, it will be 

 observed, have fallen since the 1st of September, two-thirds of 

 which fell by night, and frequently attended with most boiste- 

 rous gales. J. S. 



JVeK Mallon, Jan. 3, 1825. 



Article IV. 



Facti respecting the Boi/ing Point of Ether. By J. Bostock, 



MD.FRS. &c. 



(To the Editors of the Annals of Philosophy.) 



GENTLEMEN, Uj^nr £eclford.j)!ace, Feb. 12, 1825. 



The following facts which I have observed respecting the 

 boiling of ether, have, I beheve, not been before noticed. If 

 you think them of sufficient importance, they are much at your 

 service for insertion in the Annals. 



During the months of l)eceaiber and January, I was making 

 some experiments on the action of ether and water upon each 

 other, and particularly with 'regard to the effect produced upon 

 ether by washing it. Among other circumstances I wished to 

 ascertain the exact boiling point of ether before and after the 

 operation of washing, and to compare this with the diminution 

 of specific gravity which it experiences by this process. By 

 heating ether of the specific gravity of '755 in a matrass which 

 contained a thermometer, over a spirit-lamp,' I found that 

 ascending and descending currents began to be visible in the 

 fluid at 107°; at 110° a few small single bubbles were formed, 

 and that at 112° the ebullition was complete. It seemed, how- 

 ever, difficult to ascertain the object in view by this process, as a 

 difference of 2° generally exists between the first formation of a 

 single bubble and the production of what may be called complete 

 ebullition. Besides it was often difficult to observe the exact 

 height of a delicate thermometer, on account of the sudden 

 bursts of vapour which arose from the fluid, and it occasionally 

 happened that after ebullition had appeared to be going on at a 

 certain temperature, it would cease, and not recommence until 

 the thermometer had risen, perhaps, more than a degree. It 

 appeared, however, that ether of the specific gravity of 'TSS 

 could not be raised above the 112th degree, and that at this 

 point it was always in a state of complete ebullition. 



