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. It is not, perhaps, widely known, that Percival was a well-informed botanist. He studied this branch when a medical student under Professor Ives, and assisted his instructor in laying out a small botanical garden, the plants of which were arranged after the natural orders of Jussieu. Soon after finishing his medical education, he gave a course of lectures on botany in Charleston, South Carolina, before a very select audience, composed mostly of Ladies. The only drawback to the lecturer's success was his excessive timidity. As an evidence of the assiduity with which he botanized, it may be mentioned that he had seen the _Geranium Robertianum_ (a plant which nestles in the sunny clefts of our trap mountains) in bloom, during every month of the year. One year he found its blossoms in December, another in January, and so on, until the round of the monthly calendar was completed.