Cavendish, Hon. Henry

, son of lord Charles Cavendish (who was brother to the third duke of Devonshire), | and the lady Anne Grey, third daughter of Henry duke of Kent, was born at Nice, whither his mother had gone for her health, on Oct. 10, 1731, and after an education befitting his rank, partly at Newcombe’s school at Hackney, and partly at Cambridge, devoted his life to scientific pursuits, and became one of the most eminent chemists and natural philosophers of the age. He had studied and rendered himself particularly conversant with every part of sir Isaac Newton’s philosophy, the principles of which he applied near forty years ago to an investigation of the Jaws on which the phenomena of electricity depend. Pursuing the same science on the occasion of Mr. Walsh’s experiments with the torpedo, he gave a satisfactory explanation of’the remarkable powers of the electrical fishes; pointing out that distinction between common and animal electricity, which has since been amply confirmed by the discoveries in galvanism. Having turned his attention very early to pneumatic chemistry, he ascertained, in 1760y the extreme levity of in flammable air, now called hydrogen gas. On this discovery many curious experiments, and particularly that of aerial navigation, have been founded. In the same paths of science, he made the important discovery of the composition of water by union of two airs; and that laid the foundation of the modern system of chemistry, which rests principally on this fact, and that of the decomposition of water, announced soon afterwards by Mons. Lavoisier.

So many and such great discoveries, spread his fame throughout Europe, and he was universally considered as one of the first philosophers of his age. He combined, in the highest degree, a depth and extent of mathematical knowledge, with delicacy and precision in the methods of experimental research. It might be said of him., what perhaps could hardly be said of any other person, that whatever he has done, has been perfect at the moment of its production. His processes were all of a finished nature executed bv the hand of a master, they required no correction and though many of them were performedin the very infancy of chemical philosophy, yet their accuracy and beauty have remained unimpaired amidst the progress of discovery; and their merits have been illustrated by discussion, and exalted by time. His grand stimulus was evidently the love of truth and knowledge. Unambitious, unassuming, it was often with difficulty that he was persuaded to bring forward his important discoveries. He | disliked notoriety; he was, as it were, fearful of the voice of fame. His labours are recorded with the greatest simplicity, and in the fewest possible words, without parade or apology; and it seemed as if in publication he was performing not what was a duty to himself, but was a duty to the public. His life was devoted to science, and his social hours were passed amongst a few of his friends, principally members of the royal society. He was reserved to strangers, but where he was familiar, his conversation was lively, and full of varied information. Upon all subjects of science he was luminous and profound, and in discussion wonderfully acute. Even to the last week of his life, when he was nearly seventy-nine, he retained his activity of body, and all his energy and sagacity of intellect. In the course of his last year, he prepared and described improvements in the manner of dividing large astronomical instruments, which promise very great advantages; among his latter labours, also, may be mentioned the nice and difficult experiment by which he determined the mean density of the earth; an element of consequence in delicate calculations f astronomy, as well as in geological inquiries. He died at his house at Clapham Common, Feb. 24, 1810, leaving the greatest sum in funded property which any person perhaps ever possessed, amounting to one million two hundred thousand pounds. This he bequeathed among his noble relations. “Since the death of sir Isaac Newton,” says the eloquent professor to whom we owe a part of this character, “England has sustained no scientific loss so great as that of Cavendish.” His publications on subjects of science, which are very numerous, appeared in the Philosophical Transactions, from J7G6, whence they have been since borrowed to illustrate every scientific work of late years. ¹