the SirengtJis and Vahces of Spirituous Liquors. 3 i 



§ 1 1. The uniformity of the relation between the specific 

 gravities and the strengths of spirituous hquors depends on 

 a supposition that they are either altogether composed of 

 alcohol and water, or at least in such a state of puntv as to 

 be free from every adulteration which can materially chano-t 

 the specific gravity, whilst the quantity of the former con- 

 tinues the same ; for, unless this be the case, we shall of 

 course be unable to deduce their strength from their weio-ht. 

 The substances likely to be found Tn spirituous liquors, 

 where no fraud is suspected, are, essential oils, sometimes 

 empyreumatic, mucilaginous or extractive matter, and per- 

 haps some saccharine matter. The eflect of these, with the 

 exception of the latter, is perhaps scarcely such in the course 

 of trade as to be worth the cognizance of the excise, nor 

 could it easily be reduced to any certain rules. Essential 

 and empyreumatic oils are nearly of the same specific gra- 

 vity as spirit, or generally rather lighter; and therefore, 

 notwithstanding the mutual penetration, will probably make 

 but little change in the specific gravity of any spirituous 

 liquor in which they are dissolved. The other substances 

 are all heavier than spirit ; the specific gravity of common 

 gum being 1482, and of sugar 1606, according to the ta- 

 bles of M. Brisson. The efltTts of them, therefore, will be 

 to make spirituous liquors appear less strong than they 

 really are. With a view of determining this matter, Dr. 

 Dollfuss evaporated lOOO grains of brandy, and the same 

 quantity of rum, to dryness : the former left a residuum of 

 40 grains, the latter only of 8^ grains. The 40 grains of 

 residuum from the brandy, dissolved again in a mixture of 

 100 of spirit with 50 of water, increased its specific gravity 

 •00041 : hence the effect of this extraneous matter^ upon 

 the specific gravity of the brandy containing it, would be 

 to increase the fifth figure b»y six nearly, which is about 

 equal to the effect which would be produced in the above- 

 mentioned mixture, by the addition of a pint of water to 

 100 gallons of the spirit; a quantity much too minute for 

 the attention of government. It appears, indeed, somewhat 

 remarkable, both that so large a proportion of residuum 

 should have been lel't, and that upwards of I-4lh by wcio-ht 

 of this extractive matter should not have occasioned a 

 greater difference than 1 -2000th part in the specific gravity 

 of this diluted spirit. Saccharine matter operates much 

 more powerfully in this respect. If a quantity of sugar be 

 dissolved in proof spirit, it will become very coiisiderai)!y 

 increased in its weight, and consequently diminished in its 

 apparent strcnslh and value. There wiirperhnj^s, however, 



be 



