--YOUNG, C. A. _General Astronomy (Boston, 1891), Art. 653._ =1560.= I am convinced that the future progress of chemistry as an exact science depends very much indeed upon the alliance with mathematics.--FRANKLAND, A. _American Journal of Mathematics, Vol. 1, p. 349._ =1561.= It is almost impossible to follow the later developments of physical or general chemistry without a working knowledge of higher mathematics.--MELLOR, J. W. _Higher Mathematics (New York, 1902), Preface._ =1562.= ... Mount where science guides; Go measure earth, weigh air, and state the tides; Instruct the planets in what orb to run, Correct old time, and regulate the sun. --THOMSON, W. _On the Figure of the Earth, Title page._ =1563.= Admission to its sanctuary [referring to astronomy] and to the privileges and feelings of a votary, is only to be gained by one means,--_sound and sufficient knowledge of mathematics, the great instrument of all exact inquiry, without which no man can ever make such advances in this or any other of the higher departments of science as can entitle him to form an independent opinion on any subject of discussion within their range._ --HERSCHEL, J. _Outlines of Astronomy, Introduction, sect. 7._