364 Dr. Ure's new experimental researches 
upper range, the correspondence is as go*)d as the delicacy 
of the experiments at such temperatures could permit us to 
expect. The experiments have been presented without modi- 
fication. I must own, that when first the above perfect coin- 
cidence appeared, it gave me no small pleasure, as it led me 
to suppose that I had discovered the hidden chain of nature. 
In treating of the vapour of alcohol, Mr. Dalton consi- 
ders it as irregular in the progress of its elastic force by heat, 
owing to its not being a homogeneous liquid. He suspects 
“ that the elastic force in this case is a mixture of aqueous 
and alcoholic vapour.” I cannot see the cogency of this 
argument ; for, if the separate bodies have a regular pro- 
gression, the mixture ought not surely to be anomalous. I 
believe, however, that if the experiments were made with 
due accuracy, alcohol would be found as methodical in the 
elastic march of its vapour as other bodies. The following 
table will afford satisfactory proofs of the justness of these 
views. For absolute alcohol, the progression is probably as 
simple as that of the preceding vapours. But for alcohol, 
sp. gr. 0.813, which though highly rectified, contains not a 
little water, we should expect it to result from a composition 
or modification of ratios. After some search on this principle, 
I accordingly found it. Starting from the boiling point 174°, 
or for the convenience of comparison with the table, from 
the decade 170°, we move not by a unit, as before, but by a 
unit and a tenth ; or the initial ratio 1.26 is affected at each 
step or term of 10 3 , with the number + 0.011, the signs being 
employed as in the preceding cases. 
