XVII. DISTILLED LIQUORS. 



1 SPECIFIC GRAVXTY.-TENTATIVE. 



Determine the specific gravity at -^ bj' means of a pycnometer or a small, 

 accurately graduated hydrometer. 



2 ALCOHOL BY WEIGHT.— OFFICIAL. 



Weigh 20-25 grams of the sample into a distillation flask, dilute with 100 cc. of 

 water, distil nearly 100 cc. and weigh the distillate or make to volume at 20°C. and 

 in either case, determine the specific gravity as directed under 1 . Obtain the corre- 

 sponding percentage of alcohol by weight from XVI, 5, multiply this figure by the 

 weight of the distillate, and divide by the weight of the sample taken to obtain the 

 per cent of alcohol by weight. 



The alcohol content of the distillate may be checked by determining the immer- 

 sion refractometer reading and obtaining, from XVI, 6, the percentage of alcohol. 



ALCOHOL BY VOLUME. 



3 Method I.— Official. 



From the specific gravity of the distillate, obtained under 2, ascertain the cor- 

 responding percentage of alcohol by volume from XVI, 5. Multiply this figure by 

 the volume of distillate and divide by the volume of the sample (calculated from 

 the specific gravity) to obtain the percentage of alcohol by volume in the original 

 sample. 



4 Method II.— Tentative. 



Measure 25 cc. of the sample at 20°C. into a distillation flask, dilute with 100 

 cc. of water, distil nearly 100 cc, make to volume at 20°C. and determine the spe- 

 cific gravity as directed in 1 . Obtain, from XVI, 5, the corresponding percentage 

 of alcohol by volume in the distillate. Multiply by 4 to obtain the percentage of 

 alcohol by volume in the original substance. 



The alcohol content of the distillate may be checked by determining the immer- 

 sion refractometer reading and obtaining the percentage of alcohol from XVI, 6. 



5 EXTRACT.— OFFICIAL. 



Weigh, or measure at 20°C., 100 cc. of the sample, evaporate nearh' to dryness 

 on the water bath, then transfer to a water oven, and dry at the temperature of 

 boiling water for 2^ hours. 



6 ASH.-OFFICLAL. 



Proceed as directed under VIII, 4, employing the residue from the determination 

 of the extract, 5. 



7 ACIDITY.-TENTATIVE. 



Titrate 100 cc. of the sample (or 50 cc. diluted to 100 cc. if the sample is dark) 

 with N/10 alkali, using phenolphthalein as an indicator. Express the result as 

 acetic acid; 1 cc. of N/10 alkali is equivalent to 0.0060 gram of acetic acid. 



243 



