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XLV. Theory of JEtherification. By Alexander William- 

 son, Professor* of Practical Chemistry in the London Uni- 

 versity *. 



WHEN sulphuric acid is brought in contact with alcohol 

 under certain circumstances, a new arrangement is 

 effected in the elements of the alcohol, which divide into two 

 groups, forming aether and water. Now it is well known that 

 the process by which this change is effected may be repre- 

 sented in two ways, the difference of which consists in their 

 respectively selecting for starting-point a different view of the 

 constitution of alcohol. According to the one view, an atom 

 of alcohol weighs 23, and is made up of C 2 H 6 O; so that to 

 form aether, two atoms of it are needed, one of which takes 

 C 2 H 4 from the other, setting free the water with which these 

 elements were combined ; whereas, according to the other 

 view, alcohol weighs 46, and contains aether and water. These 

 are not the only points of difference which are urged ; but 

 they are the most real and tangible, and their consideration is 

 sufficient for our present purpose. If by any direct fact we 

 could decide which of these two expressions is the correct 

 one, the ground would be clear for an examination of the 

 process of aetherification itself. In order to show more clearly 

 the true meaning of the facts I have to adduce on this point, 

 I will bring them before you in the order in which they arose. 



My object in commencing the experiments was to obtain 

 new alcohols by substituting carburetted hydrogen for hy- 

 drogen in a known alcohol. With this view I had recourse 

 to an expedient, which may render valuable services on similar 

 occasions. It consisted in replacing the hydrogen first by 

 potassium, and acting upon the compound thus formed by the 

 chloride or iodide of the carburetted hydrogen which was to 

 be introduced in the place of that hydrogen. I commenced 

 with common alcohol, which, after careful purification, was 

 saturated with potassium, and as soon as the action had ceased, 

 mixed with a portion of iodide of aethyle equivalent to the po- 

 tassium used. Iodide of potassium was readily formed on the 

 application of a gentle heat, and the desired substitution was 

 effected ; but, to my astonishment, the compound thus formed 

 had none of the properties of an alcohol — it was nothing else 

 than common aether, C 4 H 10 O. 



Now this result at once struck me as being inconsistent 

 with the higher formula of alcohol ; for if that body contained 

 twice as many atoms of oxygen as are in aether, I ought clearly 



* Communicated by the Author; having been read before the British 

 Association at Edinburgh, August 3, 1850. 



