On the Strengths a?id Values of Spirituous Liquors. £05 



and he was at length induced to go throu'^h the whole series 

 anew. Of the results of these experiments sir Charles 

 Blagden laid a report before the society, which was read 

 the 22d of April 1790; and afterwards a supplementary re- 

 port, which was read the 28th of June 1792. To state 

 every thing of importance which they contain, they must 

 be copied verbatim : we shall however endeavour, with as 

 much perspicuity as we can, to trace the outlines of their 

 contents. 



The spirit at first employed by Mr. Gilpin was furnished 

 him by Dr. DoUfuss, under whose inspection it had been 

 rectified from rum supplied by government ; its specific gra- 

 vity at 60° was 825* 14, That which he afterwards used was 

 distilled for the purpose by Mr. Schmcisser, who brought 

 some of it to the specific gravity of 81 7 ; and its agreement 

 with the former with respect to its specific gravity, when 

 diluted and subjected to change of temperature, w^as tried 

 before it was employed in tlr^ experiments. The spirit, 

 however, which they thought proper to assume as what ap- 

 peared to them a convenient standard of value, ^^'as that 

 ■which has the specific gravity of 825 at 60°; and the 

 stronger alcohol which they used was therefore previously 

 diluted with distilled water to that degree of strength. 



The mixtures were made by weight, as the only accurate 

 method of fixing the proportions. It was conceived that, 

 in fluids of such very unequal expansions by heat as water 

 and alcohol, if measures had been employed, it would not 

 only have been necessary to make a different mixture for 

 every different degree of heat, but the proportions of the 

 masses w ould have been sensibly irregular; and the object in 

 view was to determine the real quantity of spirit in any given 

 mixture, abstracting the consideration of its temperature. 

 Another principal consideration was, that with a very nice 

 balance, such as was employed on this occasion, quantities 

 would be determined to much greater exactness by weight 

 than by any practicable way of measurement : the propor- 

 tions were therefore always taken by weight. A phial being 

 provided of such a size as that it should be nearly filled with 

 the mixture, was made perfectly clean and dry; and, being; 

 counterpoised, as much of the pure spirit or of distilled 

 w atcr as appeared necessary was poured into it. The weight 

 of this spirit or water was then ascertained, and the water 

 or spirit required to make a mixture of the intended |)ro- 

 portions was calculated. This quantity of fluid was then 

 added with all the necessary care, tlie last portions being 

 4 put 



