The public seldom know how much they owe to the unselfish labors of men of science. We noted recently the republication of the above named useful work in this country, by G. S. Davis, of Detroit, it having already been published in India as well as in Australia, and a translation in German for the use of the people of the Empire. We now note by a paragraph in the Melbourne Leader of April 18, that this mass of useful labor, so highly appreciated everywhere, is a free gift to the world, Dr. Mueller receiving nothing from it, yet he takes as much interest in helping and working for Mr. Davis' success with the work in our country as if there were "millions in it " as the phrase goes.