About the close of last century an imcomprehensible old gentleman had a mansion close to the British Museum. Few visitors were admitted; but those who found their way across the threshold reported that books and scientific apparatus formed its chief furniture. He likewise possessed a large band well-stocked library, collected in a house in Soho, which was thrown open to all engaged in research; and thither he himself would go, when in want of any book, signing a receipt for the volumes he procured with as much regularity as if it had been a circulating library, and he a reader, either little known or little trusted. His favourite residence, however, was a suburban villa at Clapham, almost wholly occupied as workshops and laboratory. The upper rooms constituted an astronomical observatory. The building was stuck over with thermometers and rain-gauges. On the lawn was a wooden stage, which afforded access to a large tree. All these were objects of mysterious interest and perplexity to the neighbours, who did not scruple to pronounce the owner a wizard. His appearance and conduct were, in some degree, calculated to give colour to their suspicions. His dress comprised the frilled shirt-wrist, high coat-collar, and cocked hat, that had been fashionable in the days of his grandfather. His complexion was fair; his features were small, but marked. He seemed to have no human sympathies, desired ever to be alone, shrank from strangers as from a pestilence, and avoided women with as much caution as could possibly have been exercised, without betaking himself to a hermitary. Yet he was enormously rich, was looked upon as the most accomplished British philosopher of his time; and his chemical researches, including those relating to the composition of water, had been prosecuted with so much skill and accuracy in devising and executing experiments, with so much caution and prudence in reasoning upon the conclusions to which they led, and with so much success in the result, that he was regarded as "the Newton of Chemistry."

Unlike the majority of men of science, he was of noble birth, claimed a duke for grandfather on both sides, and traced his descent through a long line of ancestors, from a chief-justice in the reign of Edward III, His father was Lord Charles Cavendish, a son of the second Duke of Devonshire, and his mother, Lady Anne, daughter of Henry Grey, duke of Kent. The latter was in bad health at the time of her marriage, and shortly after went to Nice, for the benefit of the waters, attended by her husband, and there Henry Cavendish, the future renowned chemist, was ushered into the world, on the 10th of October, 1731. Soon after their return to England, Lady Anne died, and Cavendish was thus, at the earliest age, deprived of those maternal offices and influences, which might have obviated the peculiarities he afterwards, and to the last, so prominently exhibited. There can be no doubt that his taste for science, which was his sole passion, only mistress, and absorbing pursuit through life, was inherited from his father, who was not only a philosophical experimentalist, but a good mathematician and in the last years of his life a senior member of the Royal Society. Cavendish was sent to a school at Hackney, kept by the Rev. Dr. New-come, a sound classical scholar and a sharp disciplinarian, along with his young brother Frederick, who was afterwards, as a man, distinguished alike by the eccentricity of his habits, and remarkable for his excellence and benevolence of disposition. In the papers that remain in existence relating to this educational institution, which was numerously attended by the children of the higher classes, consisting chiefly of plays acted by the boys, the name of Cavendish does not appear; and, considering his habits in after years, it is more than probable that he was already musing in solitude, and, "with thoughts for armies," achieving triumphs in those fields of science which he subsequently preferred to the excitement of senates and the fascination of gilded saloons. He remained for several years at Hackney, whence he went direct to Cambridge, and matriculated at St. Peter's College, in December 1749. Here he resided regularly till 1753, when he left without taking his degree. Among his co-temporaries were Gray the poet, and that Duke of Grafton who occupies so unenviable a position in the letters of Junius.

After leaving Cambridge, Cavendish went to London, and appears at this period to have paid a visit to Paris, in company with his brother, with whom he had little intercourse in after-life; for, though they were sincerely attached to each other, their tastes and habits were so utterly dissimilar as to preclude the possibility of very close intimacy. The following is the only conversation recorded between the brothers, and seems to confirm the statement of Cavendish having been the coldest and most indifferent of mortals. On landing at Calais they took up their quarters at an hotel for the night. In retiring to bed they passed a room in which, the door being open, they observed a corpse laid out for burial, which produced on the younger brother that solemn feeling which prompted him next day to allude to the subject.

"Did you see the corpse? "he asked, with interest.

"I did," was the cold, brief reply of the philosopher, who, most likely, was already pondering some of his great chemical experiments.

Cavendish's keen attachment to scientific pursuits had not escaped the notice and regret of his relatives, who, being aware of his unquestionable talents, were anxious that he should take that part in public life which men of his station and influence then experienced little difficulty in doing.

It may reasonably be doubted whether his peculiar bent of mind would not have disqualified him, in a great measure, from shining in the political world; but, at all events, the experiment was not to be tried; for, even at the hazard of causing displeasure, he steadily and resolutely refused to be withdrawn from those congenial and beloved studies to which he had dedicated himself for better or for worse This decision, however, is understood to have subjected him to the anger of his friends, and to narrow pecuniary circumstances; and it is related that, when he attended at the Royal Society, one of the very few places of public resort he ever ventured to appear in, his father used to give him the five shillings to pay for the dinner there—not a fraction beyond the limited sum which it cost.

It was not till he had reached the age of forty that he inherited from an uncle, who disapproved of the treatment he had met with, that vast fortune which made a French writer describe him as the richest of all the learned of his time, and the most learned of all the rich. It was after this that Ms most memorable chemical discoveries were either made or published. His researches soon rendered him a conspicuous personage in the scientific circle of London; he was a distinguished Fellow of the Royal Society, and a member of the French Institute; yet he was so far from coveting fame, that he used every means to avoid what he had fairly earned. But in spite of his efforts he became an object of interest and admiration to Europe, even whilst he could not bear to be pointed out to any one as a celebrated man, and when he never went into society, except on the occasion of some christening at the houses of his aristocratic kinsmen. Then his appearance was awkward, his maimer nervous, his speech hesitating, and his voice sharp and shrill; but, when he said anything it showed genius, and was always to the purpose. His love of solitude was so great, and his aversion to commerce with his fellow-men so inveterate, that even when the day of his dissolution arrived he insisted upon being left alone to mark its progress and die. He departed this life on the 24th of February, 1810, and was buried at All Souls' Church, Derby, leaving the world a rich legacy in the fruits of his scientific genius.