We have from the most authentic source the account of an incident which occurred on one of his rides while President. He was riding along one of the highways leading into Washington, when he overtook a man wending his way towards the city. Jefferson, as was his habit, drew up his horse and touched his hat to the pedestrian. The man returned the salutation, and began a conversation with the President--not knowing, of course, who he was. He at once entered upon the subject of politics--as was the habit of the day--and began to abuse the President, alluding even to some of the infamous calumnies against his private life. Jefferson's first impulse was to say "good-morning" and ride on, but, amused at his own situation, he asked the man if he knew the President personally? "No," was the reply, "nor do I wish to." "But do you think it fair," asked Jefferson, "to repeat such stories about a man, and condemn one whom you dare not face?" "I will never shrink from meeting Mr. Jefferson should he ever come in my way," replied the stranger, who was a country merchant in high standing from Kentucky. "Will you, then, go to his house to-morrow at -- o'clock and be introduced to him, if I promise to meet you there at that hour?" asked Jefferson, eagerly. "Yes, I will," said the man, after a moment's thought. With a half-suppressed smile, and excusing himself from any further conversation, the President touched his hat and rode on. Hardly had Jefferson disappeared from sight before a suspicion of the truth, which he soon verified, flashed through the stranger's mind. He stood fire, however, like a true man, and at the appointed hour the next day the card of Mr. ----, "Mr. Jefferson's yesterday's companion," was handed to the President. The next moment he was announced and entered. His situation was embarrassing, but with a gentlemanly bearing, though with some confusion, he began, "I have called, Mr. Jefferson, to apologize for having said to a stranger--" "Hard things of an imaginary being who is no relation of mine," said Jefferson, interrupting him, as he gave him his hand, while his countenance was radiant with a smile of mingled good-nature and amusement. The Kentuckian once more began his apologies, which Jefferson good-naturedly laughed off, and, changing the subject, had soon captivated his guest by launching forth into one of his most delightful strains of animated conversation, which so charmed Mr. ----, that the dinner-hour had arrived before he was aware how swiftly the pleasant hours had flown by. He rose to go, when Jefferson urged him to stay to dinner. Mr. ---- declined, when Jefferson repeated the invitation, and, smiling, asked if he was afraid to meet Mr. ----, a Republican. "Don't mention him," said the other, "and I will stay."