386 Chemical Society, 



80. " Some additional Remarks on Theine," byJ.Stenhouse,Ph.D. 



81. "Note on the Preparation of iEther," by George Fownes, Ph.D. 



The beautiful experiments of Mitscherlich on the indefinite con- 

 version of alcohol into aether by the same quantity of sulphuric acid, 

 seem to point out the possibility of effecting a great improvement 

 in the economical production of that important substance. It is 

 well known that in the old process, in which equal weights of acid 

 and spirit are subjected to distillation, a large quantity of alcohol 

 escapes aetherification at the commencement of the process, owing 

 to the low boiling-point of the mixture, and on the other hand, 

 much is destroyed towards the end of the distillation by the excess- 

 ive heat ; the limits of temperature within which aether is generated 

 in quantity being, as is well known, rather narrow, ranging perhaps 

 between 280° and 320°. 



In the continuous operation described by Mitscherlich such a mix- 

 ture of alcohol and sulphuric acid is made that its boiling-point shall 

 be well within the aether-producing limit, while into this mixture, 

 maintained in a state of rapid ebullition, alcohol is suffered to flow 

 in such proportion as exactly to replace the liquid which distils over, 

 and which liquid is seen to consist of a mechanical mixture of aether 

 and water with a very small quantity of unaltered alcohol. So long 

 as the temperature is properly maintained by due regulation of the 

 fire and the flow of alcohol, the distilled products do not vary, and 

 the process itself may be, it is said, continued until the oil of vitriol 

 becomes gradually destroyed by the impurities of the spirit, or lost 

 by volatilization. 



In this experiment absolute alcohol is used ; in the practical manu- 

 facture of aether, however, this is obviously impossible ; it occurred 

 to me therefore to try experimentally how far the process might be 

 carried if ordinary rectified spirit were substituted. It is stated in- 

 deed by Liebig, that under such circumstances aetherification is put 

 a stop to by the accumulation of the water, introduced with the al~ 

 cohol, gradually depressing the boiling-point of the mixture below 

 the temperature at which aether is formed, and that this happens 

 when the whole quantity of spirit used amounts to four times the 

 weight of the oil of vitriol (Annalen der Pharmacie, xxx. 136). It 

 is difficult to see how this could happen if attention were paid to 

 the temperature of the boiling liquid, since it would seem easy to 

 regulate the point of ebullition so as always to maintain the acid of 

 the same degree of concentration with respect to water. 



A mixture was made of 6 oz. by weight of concentrated sulphuric 

 acid and 3f oz. by weight of rectified spirit of sp. gr. '836 at 60°. 

 This mixture was introduced into a wide-necked flask fitted with a 

 cork pierced with three holes for the purpose of receiving a thermo- 

 meter, a narrow tube connected with a reservoir of alcohol of the 

 same density as that mentioned above, and a wide tube for convey- 

 ing the vapours to the condenser, which was a common metal worm 

 immersed in cold water. These arrangements being completed, an 

 Argand gas-lamp was placed beneath the flask, and the contents 

 made to boil ; the thermometer speedily rose to near 300° F. A 

 slender stream of spirit was now allowed to mix with the boiling 



