This paper is in continuation of one printed in vol. XV. of the Royal Society's Transactions. The object of it is to test the correctness of the method of observation, and of calculating the results, there proposed; and to compare both with those of more recent authors, particularly of M. Regnault of Paris, and of Dr Joseph Hooker.

The author finds the results of his subsequent observations in 1846 in the Alps, up to heights considerably above 10,000 feet, to agree well with those previously published, made in 1842. They combine in showing a sensibly uniform fall of the boiling point at the rate of 1° for 543 feet of ascent, which differs only 6 feet (in defect) from his previous determination.