1825.] Dr. Bostockon the Boiling Point t^ tlther. 197 



In order to obviate these difficulties, I poured a quantity of 

 ether into a wide test tube, and plunged the tube into a large 

 jar of tepid water, the temperature of which was gradually raised 

 by adding portions of hot water; I began at llO°, and was much 

 surprised to find that it was not until the water had arrived at 

 the 150th degree that the ether began to boil. Suspecting some 

 peculiarity in the tube, I employed a second and a third with the 

 same result ; but upon trying a fourth, I observed a minute 

 stream of bubbles rising up from one point of the glass, and on 

 examining the part, I perceived a small fragment of some sub- 

 stance adhering to it. This occurrence led me to try the effect 

 of introducing an extraneous body into the ether, and I accord- 

 ingly dropped into it some small chips of a cedar pencil, which 

 happened to lie on the table, when the wood was instantly 

 covered with bubbles, and the fluid was quickly brought into a 

 state of rapid ebullition, the bubbles appearing to arise, at least 

 in a great measure, from the surface of the wood. Precisely the 

 same effect was produced by portions of quill or filaments of 

 feather. 



I now reversed the experiment, and continued to dd portions 

 of cold water to the jar, in order to observe at what temperature 

 the ether would cease to boil, when I found that the same ether, 

 which scarcely boiled in a clean tube at loU°, by adding the 

 pieces of cedar, exhibited a perceptible, although slight ebulli- 

 tion, when the water was at 1U2°. When the wood was first 

 introduced, it was suspended in the upper part of the fluid, 

 and was covered with a stratum of fine bubbles ; by degrees, 

 however, it appeared to be completely soaked in the fluid, gra- 

 dually sunk to the bottom, and the ebullition nearly ceased ; but 

 by the introduction of a fresh piece, it was reproduced, and 

 might in this way be continued at pleasure. Other substances 

 were afterwards dropped into the ether; small fragments of 

 broken glass lowered the boiling point very considerably, but 

 not to an equal degree. When a small bit of metallic wire was 

 dropped into ether at 145°, a sudden and copious explosion of 

 gas or vapour was produced, and the ebullition afterwards conti- 

 nued at a much lower temperature, but the effect was so rapid 

 and violent, that I could not mark the exact number of degrees 

 ot the depression ; very nearly the same efiect was produced by 

 dropping copper filings into the ether, or immersing a thermo- 

 meter. When the ether in the clean tube was plunoed into the 

 ot water, it assumed a waved or streaked appearance from 

 rapid currents which were moving up and down it in various 

 directions ; and the process of evaporation went on so rapidly, 

 that a very sensible degree of cold v, as experienced by the finger 

 when held over the mouth of the tube. 



Although in most cases the ether in the clean tube began to 

 boil at about 150°, in some cases the water in the jar has been 



