There was, however, at this time in Heidelberg a scientist probably of greater prestige than even these, whose contemporary influence was more dominant, and whose repute is now, and likely to be hereafter more prevailing.  In my walks in a certain quiet street, I sometimes met a man who made an unusual impression of dignity and power.  He had the bearing of a leader of men in whatever sphere he might move, massive and well-statured, his dress not obtrusive but carefully appointed, with an eye and face to command.  His manner was courteous, not domineering, and I wondered who the able, high-bred gentleman might be, for he carried all that in his air as he passed along the street.  It was the illustrious Helmholtz, then in his best years, with great achievements behind him and before.  His researches in many fields were profound and far extending.  I suppose his genius was at its best when dealing with the pervasive imponderable ether that extends out from the earth into the vast planetary spaces in whose vibrations are conditioned the phenomena of light.  No subject of investigation can be more elusive.  The mind that could grapple with this and arrive at the secrets and laws of the subtle medium through which the human eye receives impression is indeed worthy of our veneration.  Probably, excepting Humboldt, no German scientist in these later centuries has reached such eminence.  The fields of the two men were widely different.  The one we know best as the scientific traveller, roaming the earth over, and reducing to ordered knowledge what can be perceived of its fauna and flora, of the strata that underlie it, the oceans that toss upon it, the atmosphere that surrounds it.  The other roved not widely, but keeping to his lenses and calculations, penetrated perhaps more profoundly.  Helmholtz, a well-born youth, began his career as a surgeon in the Prussian army, and his service there, no doubt, contributed to the manly carriage for which he was conspicuous.  He married a lady of a noble house of Wuertemberg, and moved in an environment conducive to courtly manners.  Heidelberg, like the German universities in general well understood that ability in its teachers, and not a pompous architectural display, makes a great institution.  Its buildings were scattered and unpretending.  Helmholtz had a lecture-room and laboratory apart, in a structure modern and graceful, but modest in its appeal.  Here he discoursed to reverent throngs in tones never loud or confident.  It is for wiseacres and charlatans to declaim and domineer.  The masters are deferential in the presence of the sublimities and of the intelligences they are striving to enlighten.

In Germany I saw the great lights of science from afar, coming into relations of intimacy only with one or two privat-docents, young men struggling precariously for a foothold.  One such striver I came to know well, a young man gifted but physically crippled, who, being anxious to get up his English, as I was to get up my German, entered with me into an arrangement to converse in these alternately.  We were about on a par in our knowledge or ignorance of the speech not native to us, and helped each other merrily out of the pitfalls into which we stumbled, according as English or German ruled the time.