Obituary Notices. 
541 
of the alcohol is removed and a compound formed containing 
potassium in the place of this hydrogen. It occurred to Williamson 
that if this potassium alcohol were treated with the halogen 
compound of a hydrocarbon radical the potassium and the halogen 
would unite, and a new and more complex alcohol be formed 
containing the hydrocarbon radical in place of the potassium, and 
therefore in place of the hydrogen which had been removed by 
the action of the potassium. This idea was the foreshadowing of 
a very important method of synthesis, but the result showed that 
it was not applicable in this case. By acting on potassium alcohol 
with ethyl iodide Williamson obtained indeed potassium iodide, 
but the other product was not a new alcohol but common ether. 
He at once saw the explanation of this. He regarded alcohol not 
as a compound of ether and water, the common view at that time, 
but as an intermediate substance, not Ae 2 0,H 2 0, but AeHO, in 
which the ethyl and the hydrogen are independently united to the 
one atom of oxygen, and he recognised that it is this hydrogen and 
not hydrogen of the C 2 H 5 that is replaced by potassium. “ Thus 
C H C H 
alcohol is 5 0, and the potassium compound is and by 
acting upon this by iodide of ethyl we have 
C ^ 5 0 + C 2 H 6 I = IK + ^Ao. . . . 
Alcohol is therefore water in which half the hydrogen is replaced 
by carburetted hydrogen, and ether is water in which both atoms 
of hydrogen are replaced by carburetted hydrogen, thus : 
C2H5Q C 2 H 5 q „ 
H U ’ H U ’ C 2 H 5 a 
But as the formation of ether in this way could be explained on 
the supposition that alcohol is a compound of ether and water, and 
potassium alcohol a compound of ether and oxide of potassium, 
half of the ether produced being that united with oxide of 
potassium and the other half coming from the action of the oxide 
of potassium on the ethyl iodide, Williamson devised and carried 
out a crucial experiment. By acting on potassium ethylate 
with methyl iodide and on potassium methylate with ethyl iodide 
he obtained in both cases the same product, which was not a 
