of her birth. Her maiden name was Mary Fairfax; she was of Scotch ancestry and an admiral's daughter. She was twice married, first to Captain Greig, of the Russian Navy, an officer of scientific accomplishments, and to whom she is said to have owed the mathematical and physical culture which subsequently made her name illustrious as the wife of Dr. William Somerville. She became first known by a paper in the Philosophical Transactions, printed in 1820, describing her experiments on the magnetizing power of the more refrangible solar rays. "In her experiments, sewing-needles were rendered magnetic by exposure for two hours to the violet ray, and the magnetic virtue was communicated in still shorter time when the violet rays were concentrated by means of a lens. The indigo rays were found to possess a magnetizing power almost to the same extent as the violet; and it was observed, though in a less degree, in the blue and green rays. It is wanting in the yellow, orange, and red. Needles were like-wise rendered magnetic by the sun's rays transmitted through green and blue glass." Such is the statement made by Dr. Turner in his old chemistry, but he adds that "the accuracy of the experiments had been doubted, and that the result must therefore be regarded as one of the disputed points in science." Dr. J. W. Draper went over the subject in 1835, with the sunlight of Virginia, and, although adopting far more delicate methods than Mrs. Somerville, failed to produce the alleged effects.
In 1831 Mrs. Somerville published "The Mechanism of the Heavens," an abridgment and attempted popularization of Laplace's "Mécanique Céleste," which she was induced to undertake by Lord Brougham. The "Connection of the Physical Sciences," perhaps her most valuable work, was issued in 1834, and her "Physical Geography" in 1838. Her last work, on "Molecular and Microscopical Science," published when she was near ninety years of age, is beyond doubt the most remarkable exploit of her life. It is a survey of what has recently been done in the field of Molecular Physics, describes the brilliant discoveries in dialysis and atmolysis, the crystalline and colloid states of matter, spectrum analysis in its celestial applications, the microscopical structure of the vegetable world, and the physics of organization, and all in a constantly clear and often an attractive style. Mrs. Somerville was the recipient of many honors on account of her scientific labors. She received a pension from the Government, was made an honorary fellow of the Royal Astronomical Society, at the same time with Miss Caroline Herschel, received a gold medal from the Royal Geographical Society, and had her bust placed in the library of the Royal Society. She maintained her interest in the movements of the scientific world, was supplied with the latest works in various branches of knowledge, and kept up her correspondence with many of the leading mathematicians and physicists, to within a few weeks of her death. It has to be added that Mrs. Somerville did not neglect the lighter accomplishments and tastes of her youth, but continued her painting, and music, and even her lace-work and other feminine trifles.
If it be asked how she contrived to do these things which are such consumers of time, while also making such extensive scientific acquisitions, the reply is, first, that she was a woman of great capacity and great industry; and, second, that her scientific work was by no means of that highest or creative kind which is produced only by genius and requires the concentration of a life within a narrow sphere of effort. We prefer, however, to abstain from estimating Mrs. Somerville's intellectual character, but will quote the opinions expressed upon this subject by her own countrymen. The Saturday Review says: