It cannot be doubted that the great author, in the solitude of his study, has often created an epoch in the annals of mankind. A single man of genius arose in a barbarous period in Italy, who gave birth not only to Italian, but to European literature. Poet, orator, philosopher, geographer, historian, and antiquary, PETRARCH kindled a line of light through his native land, while a crowd of followers hailed their father-genius, who had stamped his character on the age. DESCARTES, it has been observed, accomplished a change in the taste of his age by the perspicacity and method for which he was indebted to his mathematical researches; and "models of metaphysical analysis and logical discussions" in the works of HUME and SMITH have had the same influence in the writings of our own time. Even genius not of the same colossal size may aspire to add to the progressive mass of human improvement by its own single effort. When an author writes on a national subject, he awakens all the knowledge which slumbers in a nation, and calls around him, as it were, every man of talent; and though his own fame may be eclipsed by his successors, yet the emanation, the morning light, broke from his solitary study. Our naturalist, RAY, though no man was more modest in his claims, delighted to tell a friend that "Since the publication of his catalogue of Cambridge plants, many were prompted to botanical studies, and to herbalise in their walks in the fields." Johnson has observed that "An emulation of study was raised by CHEKE and SMITH, to which even the present age perhaps owes many advantages, without remembering or knowing its benefactors. ROLLIN is only a compiler of history, and to the antiquary he is nothing! But races yet unborn will be enchanted by that excellent man, in whose works 'the heart speaks to the heart,' and whom Montesquieu called 'The Bee of France'." The BACONS, the NEWTONS, and the LEIBNITZES were insulated by their own creative powers, and stood apart from the world, till the dispersers of knowledge became their interpreters to the people, opening a communication between two spots, which, though close to each other, were long separated --the closet and the world! The ADDISONS, the FONTENELLES, and the FEYJOOS, the first popular authors in their nations who taught England, France, and Spain to become a reading people, while their fugitive page imbues with intellectual sweetness every uncultivated mind, like the perfumed mould taken up by the Persian swimmer. "It was but a piece of common earth, but so delicate was its fragrance, that he who found it, in astonishment asked whether it were musk or amber. 'I am nothing but earth; but roses were planted in my soil, and their odorous virtues have deliciously penetrated through all my pores: I have retained the infusion of sweetness, otherwise I had been but a lump of earth!'"