the Strengths and Vahies of Spirituous Liquors. 29 



predecessors, that, without considering the elevation of the 

 ground on which wc stand, we are ahnost induced to doubt 

 wliether their intellectual powers were equal to our own. 

 The want of resource which our ancestors seem to have dis- 

 covered in their attempts to ascertain the strengths of thc»e 

 liquors, by the shaking them in a phial, liring thcni over 

 gunpowder, and a thousand other still more fallaeiou* 

 means, when the object which thev had in view was su 

 much more accurately and easily attainable by the simple 

 operation of weighing them, really appears, at first sight, 

 somewhat remarkable. The consideration of all the details 

 relative to this subject involves a number of intricate points; 

 yet the merely ascertaining the weight of a given measure 

 of any liquor by a common pair of scales would doubtlessly 

 liave afforded a better indication with regard to its strength 

 than any of the other modes of estimating it which arc un- 

 connected with the consideration of this property. It is 

 now, however, sufficiently agreed upon, that the best rtic- 

 thod of ascertaining the relative values of spirituous liquors, 

 with regard to their diflerence of strength, is by means oi' 

 their specific gravities; and the principles of this method^ 

 therefore, will form the subject of the present tract. 



§ 7. If a given bulk or measure of water and alcohol rt* 

 tnained unchanged in every temperature, and whetiier tliese 

 two fluids were mixed or separate, the ascertaining the nt-A 

 specific gravity of the latter itself, or the estimation of the 

 ^juantity of each in any compound of the two, would be a 

 matter of no difficulty : the simple rules of alligation would 

 give all that could be required in this respect. This, iiow- 

 fver, is not the case : a variation of temperature, or the 

 mixture of two spirituous compounds of diftercut t>trciigths, 

 or of any such Tujuor with water, occasions a change lu 

 the aggregate bulk of the whole which is necessary to Ik; 

 taken into consideration ; and it will therefore be requisite 

 to treat separately of tiie effect of each of these operating 

 causes. 



§ 8. It has long been known that all bodies in general, 

 whether solid or fluid, expand by heat and contract by cold ; 

 and it follows that the same quantity of any fluid which. 

 when at an elevated temperature, would till a measui-e of 

 given dimensions, nuist fall short of doing so if the K-mpe-- 

 rature should be lowered ; and, e cotwerso, the same quau- 

 lity which would be contained in the mciisure u hcu cold 

 would when heated be more than sufficient to lill it, ilioiigh 

 the absolute weight of the whole of the fluid would sull 

 continue unchanged. In sjieakingj thcrefun.-, ol a ijicasurc 



