354 
ON THE OIL OF GRAIN SPTRIT. 
Crude fusel oil, (or the oil of grain spirit) when distilled in a 
glass retort, commences to pass over about 190° Fahrenheit, and 
considerable portion is obtained below 212 ; which consists 
mostly of alcohol and water, with a small quantity of the hydra- 
ted oxide of amyl. By changing the receiver and continuing 
the operation to about 280°, a large product is obtained, consist- 
ing principally of hydrated oxide of amyl, but contaminated with 
a little alcohol and water, and a trace of less volatile oil, which 
may be found in larger quantity in the residue remaining in the 
retort. This residue is small, of an ageeable odor, and consists 
of several substances among which may be found, an oil having 
the intoxicating smell, but not the chemical properties of oenan- 
thic ether, other than a similarity in its boiling point. 
To obtain a more perfect separation of the substances contained 
in the crude oil, a small copper still was constructed, on the prin- 
ciple which is now so successfully used in the manufacture of high 
proof alcohol, and which proved highly useful for the above pur- 
pose. This still is so arranged, that the vapor which is evolved 
by the boiling liquid, passes through a series of bent tubes, each 
of which is connected with a return pipe for returning vapors 
less volatile than boiling water, back to the still. These tubes 
are enclosed in a copper funnel filled with cold water, which be- 
comes heated as the operation proceeds, and finally boils ; the 
less volatile vapors are thus prevented from passing over, and 
the alcohol and water are almost perfectly separated from the oil 
remaining in the still. If the water is then drawn off from the 
vessel containing the serpentine tube, the distillation may be 
continued till it ceases spontaneously. 
The product thus obtained, when rectified from a little dry 
caustic potash to remove coloring matter and acetic and valerianic 
acid, and again rectified from dry quick lime to remove water, 
gives pure hydrated oxide of amyl. 
The residue left in the copper still is most easily obtained by 
distillation with water, containing a little carbonate of soda to 
neutralize free the acids contained in it. A small quantity of a 
yellow oil is thus obtained, having an agreeable vinous odor sim- 
ilar to oenanthic, but unlike that ether it yields fusel oil, instead 
of alcohol, when distilled repeatedly from caustic potash. It is 
