opposition to his old friend Brewster and others, and was elected to the position at the age of twenty-four. He was an original investigator in a wide field of physics, contributed to the extension of knowledge in many directions, and was an able writer. His health failing, he resigned his chair in the Edinburgh University, and accepted the principalship of St. Andrew's, and is therefore known as Principal Forbes. He died the last day of 1868, and an elaborate biography, by three of his Scotch friends, has just been published by Macmillan, which is an extremely interesting book.
Among other subjects of his investigation were the glaciers, upon which he published an important volume. He met Agassiz in the Alps, while that gentleman was experimenting upon glacial motions, and they made observations together, but subsequently fell out with each other about the division of the honors of discovery. The complication extended, involving the claims of Bishop Bendu, Prof. Guyot, and others. In his "Glaciers of the Alps," published in 1860, Prof. Tyndall undertook to do justice to the claims of all parties. Prof. Forbes was not satisfied with the awards, and replied to Prof. Tyndall's work, vindicating his own claims to a larger share of the investigation than had been accorded him. To this Prof. Tyndall at the time made no rejoinder; but in his recently-published "Forms of Water" he restated the case in a way that was not satisfactory to Forbes's biographers, who have met it by an appendix to the volume. In the Contemporary Review for August, Prof. Tyndall returns to the question in an elaborate paper, entitled "Principal Forbes and his Biographers," of which we publish the first and last portions, that are of most general interest. We have not space for the whole article, which is long, and omitted the extended extracts from Rendu's work in French, and that portion of the argument which will mainly concern the special students of glacial literature. In an introductory note to the article, Prof. Tyndall briefly states the origin and cause of the controversy, and earnestly deprecates its present revival. He says, speaking of the biographers: "I am challenged to meet their criticisms, which, I find, are considered to be conclusive by some able public journals and magazines. Thus the attitude of a controversialist is once more forced upon me. Since the death of Principal Forbes no one has heard me utter a word inconsistent with tenderness for his memory; and it is with an unwillingness amounting to repugnance that I now defend myself across his grave. His biographers profess to know what he would have done were he alive, and hold themselves to be the simple executors of his will. I cannot act entirely upon this assumption, or deal with the dead as I should with the living. Hence, though these pages may appear to some to be sufficiently full, they lack the completeness, and still more the strength, which I should have sought to confer upon them had my present position been forced upon me by Principal Forbes himself instead of by his friends."
It is to be feared that Prof. Forbes did not sufficiently abide by the rule of life which was formed under the solemn circumstances of his father's death.
We commend to the attention of our scientific readers, with philosophical inclinations, the series of articles on "The Primary Concepts of Modern Physical Science," the first of which appears this month, on "The Theory of the Atomic Constitution of Matter." The depth and force of the criticism are only equalled by the clearness of the conceptions, and the precision and felicity of the statement. The interest of the discussion will not be lessened