I suppose, too, that other men can hardly dream of the one vast pleasure which comes to these searchers when ever so little a new truth or a fresh analogy reaches them as the result of their work.  The pursuit itself is all absorbing, all exacting, and when at last the purpose is attained, and out of darkness flashes the light of some novel law, the knowledge of some new connecting link, some simple explanation of a range of facts or phenomena, or even the discovery of a fresh analogy or homology, or of an undescribed fossil being, the purity of the pleasure which they win is something which to be understood must have been felt.  “I think,” said Jeffries Wyman once to the writer, “that the most happy and heartfilling thing in the world is to come face to face with something which no one but God ever saw before.”  How transcendent must have been this form of joy when it rewarded the first who saw the spectrum analysis of starlight in its fullness of meaning, or to him who first knew where and how the blood runs its wonderful courses!

Then, too, the life of other men, of the merchant and the lawyer, palls as age advances and its rewards are paid in dollars or in honor.  Their experiences are limited and work out, but the naturalist or investigator only gathers day by day new interests about his life of duties.  His work is as pleasant as play, and his play is usually only some new form of work.  Nature is his—­a mistress whose charms are unfading, and who is his for life.  Go to some meeting of men of science and see how this is.  The oldest has as keen a zest as the youngest, and while life becomes to others a weariness, to these men the pleasure in their steady work is absolutely unfailing.  I heard the other day a half-jesting remark at a dinner-table of men of science to the effect that life might become a tiresome thing as we grew older.  “Not for me,” said one of them, whose name is known wherever science is held in honor:  “there must be no end of Rhizopods I have never studied.”  Thus it is that men who live ever gazing at the surely widening horizon of truth, who know that they at least need never sigh for new worlds to conquer, who day by day are coming into closer company with the yet unwhispered thoughts of the great Maker, are happy and contented in the tasks to which their lives are given, and serenely patient of what their duties deny them of luxury and wealth and freedom to wander or to rest.

It might well be thought that men living so far apart from the general paths, and pursuing purposes so remote from those of the trader, would become obnoxious to that bitterest of American reproaches, the charge of being unpractical.  The directness of aim of scientific training and the lofty code of honor among students of science, with their fair share of cis-Atlantic pliability, makes them, however, most useful and trustworthy people whenever it becomes requisite to entrust to them the mixture of commercial and scientific labor