66 CHEMICAL DISCOVERY AND INVENTION 



free warehouses. During storage soluble matter is abstracted 

 from the wood of the casks, and in the subsequent treatment 

 which is required to convert the spirits into gin and other 

 beverages, small quantities of sugar, and of colouring and 

 flavouring matters are added. In these cases and also when 

 dealing with medicinal spirits, essences, and other preparations 

 distillation or other treatment is necessary since the true 

 alcoholic strength cannot be determined directly by Sikes' 

 Hydrometer, the legal instrument used by the Customs and 

 Excise officers for this purpose. A large number of samples of 

 spirituous preparations must therefore be subjected to a more or 

 less detailed chemical analysis before their true strength can be 

 ascertained. Brandy, rum, and other imported spirits and spirit 

 mixtures require similar treatment before the extent to which 

 their true alcoholic strength is " obscured " by the colouring, 

 flavouring, and other matters present in the spirit, can be 

 determined. 



Alcohol of high strength is allowed duty free for scientific and 

 manufacturing purposes, and for domestic uses such as burning 

 in spirit lamps. In most cases the alcohol for these purposes is 

 required to be " denatured " or mixed with nauseous or tell-tale 

 ingredients to prevent its consumption as a beverage or its use 

 in medicines or preparations capable of being taken internally. 

 " Mineralised methylated spirit " which is allowed to be sold 

 retail is ordinary alcohol denatured with a mixture of 10 per cent 

 of wood spirit and three-eighths of one per cent of mineral 

 naphtha. " Industrial methylated spirit " is ordinary alcohol 

 denatured with half this quantity of wood spirit without mineral 

 naphtha. The latter spirit can only be used for manufacturing 

 purposes under regulations approved by the Commissioners of 

 Customs and Excise. Other denaturants are allowed in con- 

 nection with particular manufactures. The denaturants in all 

 cases must be submitted for approval to the Government 

 Chemist, and samples are taken frequently during the manu- 

 facturing processes in which the spirit is employed, as well as 

 samples of the finished articles manufactured, in order to ascertain 

 whether the conditions imposed are being complied with. 

 Beverages and medicinal preparations in which the presence of 

 methylated spirit is suspected are also examined with a view to 

 the prevention of any illegal use of the denatured spirit. 



Fusel O7. a by-product of the manufacture of spirits, consists 



