Were it possible to collect some thoughts of great thinkers, which were never written, we should discover vivid conceptions, and an originality they never dared to pursue in their works!  Artists have this advantage over authors, that their virgin fancies, their chance felicities, which labour cannot afterwards produce, are constantly perpetuated; and those “studies,” as they are called, are as precious to posterity as their more complete designs.  In literature we possess one remarkable evidence of these fortuitous thoughts of genius.  POPE and SWIFT, being in the country together, observed, that if contemplative men were to notice “the thoughts which suddenly present themselves to their minds when walking in the fields, &c., they might find many as well worth preserving as some of their more deliberate reflections.”  They made a trial, and agreed to write down such involuntary thoughts as occurred during their stay there.  These furnished out the “Thoughts” in Pope’s and Swift’s Miscellanies.[A] Among Lord Bacon’s Remains, we find a paper entitled “Sudden Thoughts, set down for Profit.”  At all hours, by the side of VOLTAIRE’S bed, or on his table, stood his pen and ink with slips of paper.  The margins of his books were covered with his “sudden thoughts.”  CICERO, in reading, constantly took notes and made comments.  There is an art of reading, as well as an art of thinking, and an art of writing.

[Footnote A:  This anecdote is found in Ruffhead’s “Life of Pope,” evidently given by Warburton, as was everything of personal knowledge in that tasteless volume of a mere lawyer, who presumed to write the life of a poet.]

The art of meditation may be exercised at all hours, and in all places; and men of genius, in their walks, at table, and amidst assemblies, turning the eye of the mind inwards, can form an artificial solitude; retired amidst a crowd, calm amidst distraction, and wise amidst folly.  When DOMENICHINO was reproached for his dilatory habits, in not finishing a great picture for which he had contracted, his reply described this method of study:  Eh! lo la sto continuamente dipingendo entro di me—­I am continually painting it within myself.  HOGARTH, with an eye always awake to the ridiculous, would catch a character on his thumb-nail.  LEONARDO DA VINCI has left a great number of little books which lie usually carried in his girdle, that he might instantly sketch whatever he wished to recal to his recollection; and Amoretti discovered, that, in these light sketches, this fine genius was forming a system of physiognomy which he frequently inculcated to his pupils.[A] HAYDN carefully noted down in a pocket-book the passages and ideas which came to him in his walks or amid company.  Some of the great actions of men of this habit of mind were first meditated on amidst the noise of a convivial party, or the music of a concert.  The victory of Waterloo might have been organized in the ball-room at Brussels:  and thus RODNEY, at the