its vitality did not extend. There was vigor enough in certain of its departments, especially in that of civil engineering, under the charge of Professor William A. Norton; but in such cases it was a vigor due to the energy of the individual instructor, and therefore almost certain to disappear whenever he disappeared. To bring these scattered units into an organic whole, to build up a complete and consistent scheme of scientific education, which should have both definite and lofty aims, which should train men thoroughly in scientific methods, and which should continue to exist by its own inherent vitality after the men who established it should have passed away—all this became by degrees a main work of Professor Brush's life. His energy, his judgment, his executive capacity, and his devotion, soon gave him the leading direction in the affairs of the institution. He was for a long period its secretary; he has always been its treasurer; and when, in 1872, a more formal organization of its faculty was felt to be desirable, he was elected as its presiding officer, a position which he still retains. Others have done their part toward developing various departments of the school, but its growth, as a whole, the position which it has acquired among scientific institutions, whatever that position may be, has been due to him very much more than to any other one man connected with it. None are more willing to admit this than the colleagues who have coöperated with him; and it is a gratification for them to have an opportunity of saying here, without his knowledge, what would never be suffered to be printed were it submitted to his inspection.
Nor has Professor Brush been idle in his special work, in spite of the exhausting demands made upon his time and thought by the management of the Sheffield Scientific School. The series of investigations made by him on American minerals, in conjunction with Professor J. Lawrence Smith, has already been mentioned. He coöperated with Professor Dana in the preparation of the fifth edition of his treatise on "Descriptive Mineralogy," published in 1868, and an account of his special services in connection with that work will be found stated in the author's preface. To the two editions preceding, as well as to this one, he contributed analyses of minerals. He also edited the eighth, ninth, and tenth supplements to this fifth edition, as well as the appendix to it published in 1872. In 1875 he brought out also a "Manual of Determinative Mineralogy and Blowpipe Analysis." In addition to these he has been a constant contributor to the "American Journal of Science," as will be seen by the following list of articles furnished by him to that periodical:
Vol. x, p. 370: "Analyses of American Spodumene."
Vol. xviii, p. 407: "On the Chemical Composition of Clintonite (Seybertite)"; p. 415: "On a new test for Zirconia."
Vol. xx, p. 273: "On Prosopite."