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XX. Tables for reducing the Quantities by Weight, in any Mix- 
ture of pure Spirit and Water, to those by Measure; and for 
determining the Proportion , by Measure, of each of the two 
Substances in such Mixtures. By Mr. George Gilpin, Clerk 
to the Royal Society. Communicated by Sir Charles Blagden, 
Knt. Sec. R. S . 
Read June 19th, 1794. 
These tables are founded on the experiments of which the 
results were given in the Report and Supplementary Report on 
the best method of proportioning the excise on spirituous 
liquors. They are computed for every degree of heat from 30° 
to 8o°, and for the addition or subtraction of every one part 
in a hundred of water or spirit ; but as the experiments 
themselves were made only to every fifth degree of heat, and 
every five in the hundred of water or spirit, the intermediate 
places are filled up by interpolation in the usual manner, with 
allowance for second differences. 
Every table consists of eight columns, and there are two 
tables for every degree of heat. In the first column of the 
first of the two tables, are given the proportions of spirit and 
water by weight, 100 parts of spirit being taken as the constant 
number, to which additions are made successively of one part 
of water from 1 to 99 inclusively. The first column in the 
second table has 100 parts of water for the constant number, 
with the parts of spirit decreasing successively by unity, from 
N n 2 
