As science progress, it becomes more and more difficult to fit in the new facts when they will not fit in spontaneously. The older theories depend upon the coincidences of so many numerical results which can not be attributed to chance. We should not separate what has been joined together.

Annual Report of the Board of Regents of the Smithsonian Institution, 1912, The Ether and Matter (pp. 209-210), Government Printing Office. Washington, D.C. 1913