5 



METHODS FOR THE ANALYSIS OF FERMENTED AND DISTILLED 



LIQUORS. 



Add on page 77, at eiid of Section VII : 



"19. DETERMINATION OF FUSEL OIL. 



"The apparatus recommended for this determination is Brornwell's modification of 

 Roese's fusel-oil apparatus. 



"This apparatus consists of a pear-shaped bulb holding about 200 cc, stoppered at 

 the upper end and sealed at the lower to a graduated stem about 4 mm in internal 

 diameter. To the lower end of this graduated stem is sealed a bulb of 20 cc capacity, 

 the lower end of which bears a stopcock tube. The apparatus is graduated to 0.02 

 cc, from 20 cc to 22.5 cc. 



"The reagents required are fusel-free alcohol that has been prepared by fractional 

 distillation over caustic soda or caustic potash, and diluted to exactly 30 per cent by 

 volume (sp. gr.,0. 96541), chloroform freed from water and redistilled, and sulphuric 

 acid (sp. gr. 1.2857 at 15.6). 



" Distill slowly 200 cc of the sample under examination till about 175 cc have passed 

 over, allow the distilling flask to cool, add 25 cc of water, and distill again till the 

 total distillate measures 200 cc. Dilute the distillate to exactly 30 per cent by 

 volume (sp. gr., 0. 96541 at 15.6). 



"The following is an accurate method for diluting any given alcohol solution to a 

 weaker solution of definite percentage: Designate the volume percentage of the 

 stronger alcohol by V, and that of the weaker alcohol by v. Mix v volumes of the 

 stronger alcohol with water to make V volumes of the product. Allow the mixture 

 to stand till full contraction has taken place, and till it has reached the temperature 

 of the original alcohol and water, and make up any deficiency in the V volumes with 

 water. 



"Example. It is desired to dilute a distillate containing 50 per cent of alcohol by 

 volume until it contains 30 per cent. To 30 volumes of the 50 per cent alcohol add 

 enough water to make 50 volumes, or place 150 cc of the distillate in a 250 cc flask, 

 fill to the mark with water, mix, cool, and fill to the mark again. 



"Prepare a water bath, the contents of which are kept at exactly 15, and place in 

 it the apparatus (covering the end of the tube with a rubber cap to prevent wetting 

 the inside of the tube), and flasks containing the 30 per cent fusel-free alcohol, 

 chloroform, sulphuric acid, and the distillate diluted to 30 per cent by volume. When 

 the solutions have all attained the temperature of 15, fill the apparatus to the 20 cc 

 mark with the chloroform, drawing it through the lower tube by means of suction, 

 add 100 cc of the 30 per cent fusel- free alcohol and 1 cc of the sulphuric acid, invert 

 the apparatus, and shake vigorously for two or three minutes, interrupting once or 

 twice to open the stopcock for the purpose of equalizing pressure. Allow the appa- 

 ratus to stand ten or fifteen minutes in water that is kept at the temperature of 15, 

 turning occasionally to hasten the separation of the reagents, and note the volume 

 of the chloroform. After thoroughly cleansing and drying the apparatus, repeat 

 this operation, using the diluted distillate from the sample under examination in 

 place of the fusel-free alcohol. The increase in the chloroform volume with the 

 san pie under examination over that with the fusel-free alcohol is due to fusel oil, 

 and this difference (expressed in cubic centimeters), multiplied by the factor 0.663, 

 gives the volume of fusel oil in 100 cc, which is equal to the percentage of fusel oil 

 by volume in the 30 per cent distillate. This must be calculated to the percentage 

 of fusel oil by volume in the original liquor. 



"Example. A sample of liquor contains 50 per cent of alcohol by volume. The 

 increase in the chloroform volume with the 30 per cent fusel-free alcohol is 1.42 cc. 

 The increase in the chloroform volume with the distillate from the liquor under 

 examination, diluted to 30 per cent, is 1.62 cc. Difference, 0.20 cc. The volume of 

 fusel oil in 100 cc of the 30 per cent distillate then is 0.20 X 0.663 = 0.1326 cc, and by 

 the proportion 30 : 50 : : 0.1326 : 0.221, we obtain the percentage of fusel oil by vol 

 ume in the original liquor. 



