also in the habit of painting from memory.  While at Venice, he put on canvas the faces of friends at Florence whom he had not seen for months.  That the art of painting was subservient in his estimation to mechanics, is indicated by what we hear about the camera, in which he showed landscapes by day and the revolutions of the stars by night, so lively drawn that the spectators were affected with amazement.  The semi-scientific impulse to extend man’s mastery over nature, the magician’s desire to penetrate secrets, which so powerfully influenced the development of Lionardo’s genius, seems to have overcome the purely aesthetic instincts of Alberti, so that he became in the end neither a great artist like Raphael, nor a great discoverer like Galileo, but rather a clairvoyant to whom the miracles of nature and of art lie open.

After the first period of youth was over, Leo Battista Alberti devoted his great faculties and all his wealth of genius to the study of the law—­then, as now, the quicksand of the noblest natures.  The industry with which he applied himself to the civil and ecclesiastical codes broke his health.  For recreation he composed a Latin comedy called ‘Philodoxeos,’ which imposed upon the judgment of scholars, and was ascribed as a genuine antique to Lepidus, the comic poet.  Feeling stronger, Alberti returned at the age of twenty to his law studies, and pursued them in the teeth of disadvantages.  His health was still uncertain, and the fortune of an exile reduced him to the utmost want.  It was no wonder that under these untoward circumstances even his Herculean strength gave way.  Emaciated and exhausted, he lost the clearness of his eyesight, and became subject to arterial disturbances, which filled his ears with painful sounds.  This nervous illness is not dissimilar to that which Rousseau describes in the confessions of his youth.  In vain, however, his physicians warned Alberti of impending peril.  A man of so much stanchness, accustomed to control his nature with an iron will, is not ready to accept advice.  Alberti persevered in his studies, until at last the very seat of intellect was invaded.  His memory began to fail him for names, while he still retained with wonderful accuracy whatever he had seen with his eyes.  It was now impossible to think of law as a profession.  Yet since he could not live without severe mental exercise, he had recourse to studies which tax the verbal memory less than the intuitive faculties of the reason.  Physics and mathematics became his chief resource; and he devoted his energies to literature.  His ‘Treatise on the Family’ may be numbered among the best of those compositions on social and speculative subjects in which the Italians of the Renaissance sought to rival Cicero.  His essays on the arts are mentioned by Vasari with sincere approbation.  Comedies, interludes, orations, dialogues, and poems flowed with abundance from his facile pen.  Some were written in Latin, which he commanded more than fairly; some in the Tuscan tongue, of which owing to the long exile of his family in Lombardy, he is said to have been less a master.  It was owing to this youthful illness, from which apparently his constitution never wholly recovered, that Alberti’s genius was directed to architecture.