﻿Phenomena connected with the Boiling of Liquids, 167 



point, and the varied suggestions thrown out by him have each 

 served as a basis for further inquiry by subsequent observers. 

 But the difference between him and some of them consists in 

 this, that he would originate an idea, examine, and discard it 

 when seen to be no longer tenable ; they clung to the idea even 

 though it carried them into the region of error. It is the dis- 

 tinction between genius and talent, that the one originates capital, 

 and the other trades with it. 



11. In 1825 Dr. Bostock published some facts respecting the 

 boiling-point of ether*. Ether (spec. grav. 0'755) in a matrass 

 over a spirit-lamp boiled at 112° F. ; but in a test-tube put into 

 hot water it did not begin to boil until it had reached 150°, 

 and on one occasion 175°. Some bits of cedar-wood were put 

 into the ether, and it boiled at 110°; the wood was covered 

 with bubbles, until it got soaked and sank. Bits of quill, feather, 

 w r ire, pounded glass, &c. also lowered the boiling-point consider- 

 ably. After stating that copper-filings, chips of wood, &c. ap- 

 peared to produce ebullition in the ether after it had ceased to 

 boil, Dr. Bostock says, u Plunging a thermometer into ether 

 caused the production of the bubbles at a temperature many 

 degrees below the point at which ebullition took place without 

 the thermometer ; but the effect of the thermometer after a short 

 time was no longer perceptible, and I observed that by alter- 

 nately plunging the thermometer into the ether and removing it 

 from the fluid, the bubbles were produced at each immersion." 

 The various nuclei above referred to are said to act by carrying- 

 down air into the ether, and as soon as the air is discharged they 

 cease to act. 



12. Dr. Bostock' s interesting paper called attention to some 

 processes in the useful arts adopted with a view to facilitate the 

 process of boiling. Thus Mr. Baldf notices a practice among 

 the engine-keepers of Scotland, when the ordinary supply of 

 steam cannot be raised from the boiler, of throwing in about a 

 bushel of the radicles of barley, separated during the process of 

 cleaning the malt and called " comings." When steam is again 

 raised, the effect is immediately apparent ; " for not only is there 

 a plentiful supply of steam for producing the full working speed 

 of the engine, but an excess going to waste at the safety-valve. 

 This singular effect will continue several days." So also in dis- 

 tilling ardent spirits on a large scale, when converting the fer- 

 mented wash into "low wines," it is usual to throw a bit of soap 

 into the still every time it is charged. This causes the steam to 

 rise more quickly, and to be freer from the residual matter of the 

 process. 



* Annals of Philosophy, N. S. vol.ix. p. 196. e 

 t Edinb. Phil. Joura. vol. iL p. 340. 



