The mere suspicion of scientific thought or scientific methods has a great charm in any branch of literature, however far it may be removed from actual research.  Poe’s tales, for example, owe much to this effect, though in his case it was a pure illusion.  Jules Verne also produces a charmingly credible effect for the most incredible things by an adept use of a considerable amount of real knowledge of nature.  But most gracefully of all does it shine in the lighter form of essay, where playful thoughts draw their analogies and illustrations from actual fact, each showing up the other, and the combination presenting a peculiar piquancy to the reader.

Where could I get better illustration of what I mean than in those three little volumes which make up Wendell Holmes’ immortal series, “The Autocrat,” “The Poet,” and “The Professor at the Breakfast Table”?  Here the subtle, dainty, delicate thought is continually reinforced by the allusion or the analogy which shows the wide, accurate knowledge behind it.  What work it is! how wise, how witty, how large-hearted and tolerant!  Could one choose one’s philosopher in the Elysian fields, as once in Athens, I would surely join the smiling group who listened to the human, kindly words of the Sage of Boston.  I suppose it is just that continual leaven of science, especially of medical science, which has from my early student days given those books so strong an attraction for me.  Never have I so known and loved a man whom I had never seen.  It was one of the ambitions of my lifetime to look upon his face, but by the irony of Fate I arrived in his native city just in time to lay a wreath upon his newly-turned grave.  Read his books again, and see if you are not especially struck by the up-to-dateness of them.  Like Tennyson’s “In Memoriam,” it seems to me to be work which sprang into full flower fifty years before its time.  One can hardly open a page haphazard without lighting upon some passage which illustrates the breadth of view, the felicity of phrase, and the singular power of playful but most suggestive analogy.  Here, for example, is a paragraph—­no better than a dozen others—­which combines all the rare qualities:—­

“Insanity is often the logic of an accurate mind overtasked.  Good mental machinery ought to break its own wheels and levers, if anything is thrust upon them suddenly which tends to stop them or reverse their motion.  A weak mind does not accumulate force enough to hurt itself; stupidity often saves a man from going mad.  We frequently see persons in insane hospitals, sent there in consequence of what are called religious mental disturbances.  I confess that I think better of them than of many who hold the same notions, and keep their wits and enjoy life very well, outside of the asylums.  Any decent person ought to go mad if he really holds such and such opinions....  Anything that is brutal, cruel, heathenish, that makes life hopeless for the most of mankind, and perhaps for entire