198 Dr. Bostock on the Boiling Foint of Ether. [March, 



raised to a higher temperature without producing ebullition, in 

 one instance as high as 175°, with the formation of only one or 

 two single bubbles. In this case a fragment of glass produced 

 a copious ebullition, which continued until the fluid was cooled 

 to 1 25°, when the effect was again reduced to the discharge of 

 a few single bubbles ; a cedar chip was then introduced, and pro- 

 duced a rapid ebuUition. In one experiment, the three bodies, 

 copper fiUngs, fragments of glass, and chips of wood, were 

 added in succession to the same portion of ether, and they each 

 of them appeared to have the effect of producing ebullition 

 when it had ceased from the action of the body previously em- 

 ployed. Plunging a thermometer into the ether caused the 

 production of the bubbles at a temperature many degrees below 

 the point at which ebullition took place without the thermome- 

 ter, but the effect of the thermometer was, after a short time, no 

 longer perceptible, and I observed that by alternately plunging 

 the thermometer into the ether, and removing it from the fluid, 

 the bubbles were produced at each immersion. 



It appeared that in order to produce the ful effect with the 

 pieces of cedar wood, it was necessary that they should be per- 

 fectly dry ; and I also found that wood which had been once 

 employed, although perfectly dry, was not so powerful as fresh 

 pieces : in one case by adding fresh bits of wood successively 

 to a portion of ether, the boiling point was lowered from 150° to 

 96^ 



o 



The effect of the pieces of cedar appeared more remarkable 

 by plunging into the same jar of water two tubes of ether, one 

 without any addition, the other with the chips ; in one experi- 

 ment when the ether alone scarcely boiled at 165°, emitting 

 only occasional single bubbles, the tube containing a piece of 

 cedar was in violent ebullition; the temperature was gradually 

 lowered ; and even at 102°, the formation of a continued stream 

 of small bubbles was very perceptible. 



In order to observe whether any thing of a similar kind could 

 be perceived with respect to alcohol, a portion of alcohol of 

 specific gravity '848 was heated in a matrass over a spirit-lamp; 

 a thermometer being immersed in the fluid stood at 182°; the 

 lamp was removed, and the ebullition ceased ; but upon drop- 

 ping into the alcohol a cedar chip, a fine streani of bubbles was 

 observed to issue from it ; the temperature of the fluid was now 

 14° below its former boiling point. Into another portion of 

 alcohol which appeared to be near the boiling point, as was indi- 

 cated by the appearance of rapid currents and by a slight hissing 

 noise, a few copper filings were dropped ; the ebullition was 

 considerably promoted, and proceeded, as it were, by sudden 

 starts, the bubbles always proceeding from the filings. In a later 

 experiment, the boiling point of the alcohol was reduced as 

 much as 30° and 40°, by dropping in successive pieces of the 

 cedar wood. 



