The marriage of persons nearly related by blood is apt to engender cerebral weakness in the offspring. The first-born of cousins-german, James Boswell suffered from an imperfect and morbid organization. Mr. Carlyle’s analysis of his mental condition we cordially accept, “The highest [quality],” writes Mr. Carlyle, “lay side by side with the lowest, not morally combined with it and spiritually transfiguring it, but tumbling in half-mechanical juxtaposition with it; and from time to time, as the mad alternative chanced, irradiating it, or eclipsed by it.” Around his intellectual nature hovered a dark cloud, while there was light within; the cloud was malformation or disease, but the morbid element did not extinguish the internal fire. Boswell’s perceptive power was of the highest order; he could retain and reproduce scenes and conversations with the naturalness of reality. A literary Pre-Raffaelite, his observation was acute in proportion as his reflective powers waned or slept; what he saw and heard he set forth forcibly and without embellishment. The assertion of Lord Macaulay that the “Life of Johnson” was due to the author’s weakness requires no serious refutation. Boswell produced the best biography in the language, because he was the best fitted for the task. Like the astronomer who points his telescope to the heavens in a darkened room, he concentrated his mental energies on the objects of his reverence, and with photographic accuracy depicted all that he surveyed. In proportion as he failed to develop his own intellectual nature, he succeeded in delineating the intellectual character of others. A mirror true and transparent lay under the opaque cloud, and reflected outward what a healthier intellect had appropriated and transfused. If in respect of mental phenomena the figure is admissible—the reflective faculty which is ordinarily concave and thereby receptive, was in the mind of Boswell convex and radiating outwards. The cords which fettered his understanding braced his perception and nerved his memory. He showed strength in weakness. The dry rod budded. The grey ruin was mantled by the green ivy. The fool prates unconscious of his folly; the maniac is happy in his chain. Boswell was conscious of his weakness,—hence his habitual melancholy. To Mr. Temple he early spoke of madness existing in his family, and afterwards described himself as partially insane. In his journal he compares his head to a tavern usurped by low punch drinkers, whom he could not displace. Such an unhappy consciousness might have led to reckless perversity, or hopeless inaptitude. In Boswell it stimulated to untiring effort, life-long energy. His vanity and vacillation and rashness were attendant on a distempered brain—his literary achievements were the result of a successful conflict with constitutional disorder.