Note on the examination of whisky and other spirits, for methylated spirit and fousel oil

A. Dupré
1876 The Analyst  
EXAMINATION FOR METHYLATED SPIRIT. Now and then we hear of a whisky supposed to be adulterated with methylated spirit. I myself have had several such suspected whiskies t o examine, but failed to detect such an adulterant. My belief is that such adulteration is extremely rarely if ever practised, and that most, if not all, of the cases reported, are based on an error in analysis. Under these circumstances, I have thought it might be of interest to other analysts to describe the method I have
more » ... he method I have adopted for some time past, for testing spirits suspected of being adulterated with methylated spirit. Five fluid ounces of the suspected spirit are distilled twice, having been rendered alkaline the first time, and acid the second time, about two-thirds being distilled over each time. The distillate is now shaken up with dry potassium carbonate, and, after standing over night: the upper layer is taken off by a syphon or pipette, and again twice distilled, about half an ounce being driven over this time. This last half-ounce will be found to contain any methylic alcohol present in the original five ounces. All the distillations should be conducted in an apparatus having the receiver connected air-tight with the condenser, and furnished with a mercury valve, allowing of expansion and contraction of the air, but presenting loss by evaporation during the distillation. About one-third of this distillate is now diluted to a strength of from 10 to 15 per cent. by the addition of distilled water, or 70 fluid grains are made up to about
doi:10.1039/an8760100004 fatcat:af24ai7ekjb25cy2y3rr6m3xqu