gjQg IMPROVEMENT IN PREPARING ETHER. 



acid should never compose more than two thirds of the con-> 

 tents of the retort,, and that the alcohol should be scarcely 

 ever less than the other third*. In this way the sulphuric 

 acid is prevented from burning the alcohol to its loss, and 

 we obtain- none of the results of a decomposition carried too 

 far, which is injurious to the etherification, and immediately 

 follows it. We shall then have a better product, and in 

 larger quantity; and the production qf ether will continue, 

 till the sulphuric acid is so much diluted by the water 

 formed and separated, as to be unable to effect any change 

 in the alcohol. 



Appa-atus. The particular kind of funnel, which has facilitated my 



malting" ether by means of the phosphoric acidf, and is ap- 

 plicable to many other chemical processes, enabled me to 

 carry this theory into practice in the following manner. 



tmpmv&d pro- To a large tubulated glass retort, placed on a sand heat, 

 I adapted a glass worm immersed in a vessel of cold water. 

 The extremity of the worm was inserted into the neck of a 

 large bottle, between which and a second bottle filled with 

 water a communication was established by means of a si-. 

 phon. Into the retort I introduced ten kilogrammes [22lbs. 

 avoird.] of sulphuric acid concentrated to 66°. In the tu- 

 balure was inserted the funnel with two cocks, so that its 

 pipe descended nearly to the bottom of the retort, passing 

 through the sulphuric acid. Ten kilogrammes of alcohol 

 at 36° of Beaume's areometer were then poured in quickly, 

 being conveyed through the acid by means of the funnel. 

 The mixture was very well effected, though with violence ; 

 and it was the less coloured in proportion as the introduc- 

 tion of the alcohol was more speedy. The distillation was 

 kept up by means of a fire under the retort; and as soon 

 as about two kilogrammes had passed over, ten kilogrammes 



Thefniddie * The proportions of equal parts of sulphuric acid and spirit of 



pjoduet best, wine, constantly adopted, appear to be most suitable. It is to be ob- 

 served however, notwithstanding the utmost care taken to separate the 

 alcohol, that comes over first, the product that follows does not attain 

 the lightness, that constitutes true ether, till toward the middle of the 

 process. 



-J See Journal, vol. XVIII, p. 64, and PI. II, fig. 4. 



Of 



