Till within a few days of his death, Dr. Cartwright retained full possession of his mental faculties, and attained, at the time of his decease in 1823, the age of eighty-one. His remains were interred in the church at Battle, in Sussex. _Memoir of Dr. Edmund Cartwright._ London, 1843.--_Stuart's Anecdotes of the Steam-Engine._ London, 1829. THE HON. HENRY CAVENDISH, F.R.S. Born October 10, 1731. Died February 24, 1810. Henry Cavendish, the third in order of time among the four great English pneumatic chemists of the eighteenth century,[12] was the younger son of Lord Charles Cavendish, whose father was the second Duke of Devonshire. His family trace back their descent in unbroken and unquestionable links to Sir John Cavendish, Lord Chief Justice during the reign of Edward III. The great majority of the distinguished chemists of Great Britain have sprung from the middle and lower ranks of the people, but in this respect Henry Cavendish presents a remarkable exception. He was moreover immensely wealthy, so much so, that it has been epigrammatically remarked of him, "That he was the richest of all wise men, and probably, too, the wisest of all rich men;" yet no one could well be more indifferent than he, to the external advantages which are conferred by birth and fortune. Few particulars are known of his early life. He was born at Nice, whither his mother, who died when he was two years old, had gone for the sake of her health. In 1742 Cavendish became a pupil at Dr. Newcome's school at Hackney, continuing his studies there until he had reached his seventeenth year, when he went to Cambridge, where he matriculated in the first rank on the 18th of December, 1749. He remained at this university until 1753, but did not graduate. After leaving Cambridge, the personal history of Cavendish becomes a blank for the next ten years. He joined the Royal Society in 1760, but did not contribute anything to its 'Transactions' until the year 1766, when he published his paper 'On Factitious Airs,' which contains the first distinct exposition of the properties of hydrogen, and the first full account of those of carbonic acid; and a paper published by him in the following year may be considered as a still further extension of his research into the properties of this acid.