on Spirituous Liquors. 427 
greatest when the mixture consisted of 85 parts of water, by 
weight, to 100 of alcohol. This difference, however, small as 
it was, afforded sufficient reason for repeating all the former 
experiments, conjointly with the new set for dilute spirits, so 
as to make one entire series, with the same spirit, and executed 
throughout in an uniform manner. To obviate the error 
from evaporation in this series, and ascertain what each mix- 
ture really lost of its strength during the operation, all the 
fluids were first weighed at 60°, before they were cooled down 
to 30° ; from 30° to ioo°, they were weighed at every 5 de- 
grees, as before, consequently a second time at 6o° ; and lastly, 
after having been heated to ioo°, they were again brought to 
6o°, and weighed at that point a third time. The difference 
between these weights, at the beginning, middle, and end of 
the experiment, was applied, in due proportion, to correct 
the numbers of the respective intervals between them ; by 
which means it is believed that the error arising from the gra- 
dual evaporation of the spirit, during the experiment, has been 
made to disappear. Mr. Gilpin having also observed, that 
the spirits adhering to the sides of the funnel which he em- 
ployed to fill up the weighing-bottle, grew weak by the 
evaporation, and so diluted the fresh spirit poured into the 
funnel, determined to use a smaller instrument of this kind, 
namely, such an one as would not hold more than 13 grains of 
spirit ; in which a less surface being left wet when the spirit 
ran out, the error from this cause would be proportionably 
diminished. 
Under all these precautions were the experiments made, of 
which the results are given in the following tables. They 
are drawn up exactly like the tables in the former Report * 
