to question him.  On the whole, I do not think it would be going too far to apply to him the above-named moralist’s description of the wise man:—­“He reproves nobody, praises nobody, blames nobody, nor even speaks of himself; if any one praises him, in his own mind he contemns the flatterer; if any one reproves him, he looks with care that he be not unsettled in the state of tranquillity that he has entered into.  All his desires depend on things within his power; he transfers all his aversions to those things which Nature commands us to avoid.  His appetites are always moderate.  He is indifferent whether he be thought foolish or ignorant.  He observes himself with the nicety of an enemy or a spy, and looks on his own wishes as betrayers.”

Percival’s solitary habits, combined with the invariable seriousness of his manner, led many persons to believe him melancholy, and even disposed to suicide.  He did, indeed, confess to me, that he sometimes felt giddy on the edge of a precipice.  This was his nearest approach, I am confident, to the idea of self-destruction.  While we were examining the great iron furnaces of Salisbury, he told me that he was afraid of walking near the throat of a chimney when in blast, and that more than once he had turned and run from the lurid, murky orifice, lest a sudden failure of self-control should cause him to reel into the consuming abyss.  No,—­Percival neither felt nor expressed disgust with life.  On the contrary, he was strongly attached to it; the acquisition of knowledge clothed it with inexpressible value; the longest day was ever too short to fulfil his designs.  Like the wise, laborious men of all ages, he almost repined at the swiftness of the years.  “I am amazed at the flight of time,” he said to me, on the arrival of his forty-second birthday; “it seems only a year since I was thirty-two;—­I have lost ten years of my life.”

Before entering upon the survey of Connecticut, he was not specially devoted to any one branch of physics, although his tastes inclined him most toward geology.  While he could sympathize perfectly, he said, with those who threw their whole force into a single study, he felt himself attracted equally by the entire circle of Nature, and thought omniscience a nobler object of ambition than any one science.  He admitted that the search after all knowledge is incompatible with eminence in any particular department; but he believed that it affords higher pleasure to the mind, and confers ability to do signal service to mankind in pointing out the grand connections, the general laws, of Nature.