In this department, as in all the rest, Florence was the seat of supreme mental power during the age of Leo X.; she fostered the genius which spread widely in beauty and might. In the fifteenth century, an ancient and authentic copy of the Justinian constitutions was captured at Pisa, and given by Lorenzo de Medici to the custody of Politiano, the most distinguished mediæval professor of legal science. He corrected numerous manuscripts, supervised the publication of repeated editions, and prepared the way for all the great improvements which, in his profession, have since been made. Politiano and Lorenzo, as they together took daily exercise on horseback, were wont to converse on their morning studies, and this was characteristic of the intellectual life of that age and city. The vivifying light which began to pour on a hemisphere was especially concentrated on the Tuscan capital, and all the sciences simultaneously awoke from torpor under the invigorating beams. Like a sheltered garden in the opening of spring, Florence re-echoed with the earliest sounds of returning energy in every walk of scientific invention. The absurdities of astrology were exposed, and legitimate deduction was substituted in the place of conjecture and fraud. Antonio Squarcialupi excelled all his predecessors in music, and Francesco Berlinghieri greatly facilitated the study of geography. Lorenzo de Medici himself gave especial attention to the science of medicine, and caused the most eminent professors to prosecute their researches under the auspices of his name and bounty. Paolo Toscanelli erected his celebrated Gnomen near the Platonic academy; and Lorenzo da Volpaja constructed for his princely namesake a clock, or piece of mechanism, which not only marked the hours of the day, but the motions of the sun and of the planets, the eclipses, the signs of the zodiac, and the whole revolutions of the heavens. The study of scientific progress requires us again to notice the wonderful use which Providence makes of the three original elements of post-diluvian humanity in the execution of infinite designs. The Arabians were a Shemitic race, raised into power in near neighborhood to the heritage of Ham, and were the contributors of numerous mental stores which were happily adapted yet further to augment the superiority of Japhet. These children of Ishmael existed at a gloomy period, and performed a most important work. They drew from the last living sources of Grecian wisdom, and directed numerous new tributaries into the great central current of civilization.