DISTILLED LIQUORS: WHISKY (RYE, BOURBON AND 

 SCOTCH), BRANDY (COGNAC) AND GIN. 



By W. C. Holmes. 



{From the Laboratory for the Investigation of Foods and Drugs, 

 Bureau of Science. ) 



I. A Study of the methods of analysis and some suggested improvements. 

 II. Analyses of distilled liquors entering the' port of Manila. 



I. A STUDY OF THE METHODS OF ANALYSIS AND SOME SUGGESTED 

 IMPROVEMENTS. 



A considerable number of analyses of distilled liquors have recently 

 been carried out at this laboratory and in the course of this work several 

 departures from the methods adopted by the Association of Official 

 Agricultural Chemists have been considered advisable. 



In the determination of volatile acidity, the method of adding 25 cubic 

 centimeters of water to 200 cubic centimeters of vhe sample and slowly dis- 

 tilling off 200 cubic centimeters of distillate, has been replaced by one in which 

 100 cubic centimeters of the sample are distilled with the direct flame until 

 the volume has diminished to about 30 cubic centimeters and then the distillation 

 is continued with steam, together with the direct flame, the volume of liquid 

 in the distilling flask being kept nearly constant, until 500 cubic centimeters 

 of distillate are obtained. Aliquot portions of the distillate are taken for the 

 determination of alcohol, volatile acids, esters, and aldehydes. This distillate 

 is too dilute for the accurate colorimetric determination of furfurol. In many 

 cases, however, this is of too little importance to necessitate a separate distillation. 



This modification of the method gives higher and more accurate values 

 for the volatile acids and is less affected by minor variations in the 

 manipulation. The determination of alcohol in a distillate obtained in 

 this manner is sufficiently accurate for the ordinary purposes of analysis, 

 and if necessary, in special cases, may be supplemented by a determina- 

 tion according to the official method. 



The colorimetric method for the determination of aldehydes has not 

 proven as- satisfactory as the following procedure based on the method 

 of M. Kipper. 1 



One hundred cubic centimeters of distillate are pipetted into an Erlenmeyer 



N 

 flask, 25 cubic centimeters of -^ sodium hydrogen sulphite solution added, the 



l Monatsh. f. chem. (1900), 21, 1079. 



• 23 



m 



