youthfulness of her manner, and her light and graceful figure, to the end of her life. She was married in 1804 to Mr. Samuel Greig, Russian consular agent in London, who has been credited with encouraging her scientific tastes, but incorrectly. Her daughter, Martha Somerville, says that "Mr. Greig took no interest in science or literature, and possessed in full the prejudice against learned women which was common at that time." But he did not prevent her from studying. After three years of married life she returned, a widow, to her father's house in Burntisland, with two little boys, one of whom died in childhood. With her second husband, Dr. William Somerville, whom she married in 1812, "she found sympathy with her intellectual tastes, and a stimulus to her energy for culture." Nevertheless, his sister had written to her on the first announcement of the engagement, expressing the hope that now she would give up her foolish manner of life and studies, and make a respectable and useful wife. Dr. Somerville having been appointed Inspector of the Army Medical Board and Physician to Chelsea Hospital, they removed to London in 1816. Here Mrs. Somerville introduced herself to the scientific world and attracted attention by some experiments on the magnetic influence of the violet rays of the solar spectrum, the results of which were published in the "Philosophical Transactions" of 1826.
In the year following the reading of this paper, Lord Brougham proposed to Mrs. Somerville to write for the series of publications of the Society for the Diffusion of Useful Knowledge an epitome or popular exposition of Laplace's philosophy, as laid down in his "Mécanique Céleste."' Acting upon this suggestion, she composed her "Celestial Mechanics," a work in which, though it is founded on Laplace's treatise, the author did not hesitate to express her own independent opinion of the value of the great astronomer's various propositions. The book proved to be too large and elaborate for the library for which it had been primarily intended—or, as Sir John Herschel expressed it, "written for posterity, and not for the class whom the society designed to instruct"—and was published separately, in 1831. It made her famous. The approval which it won, says "Nature" in a leading article, "from the first mathematicians and physicists of the day, seems to have surprised no one more thoroughly than the writer herself, who had carried on her studies with such unostentatious industry within her own home that she was scarcely conscious how exceptional were her attainments." On the recommendation of Professors Whewell and Peacock, the "Mechanism of the Heavens" was introduced upon the list of studies prescribed by the University of Cambridge as "essential to those students who aspire to the highest places in the examinations."
In 1834 she published "The Connection of the Physical Sciences," a work which was highly praised in the "Quarterly Review," was spoken of by Humboldt as "generally so exact and admirable a trea-
