But it was outside of the circle of the theatrical company with which he was associated in New Orleans that Forrest found the most rich and decisive influences, at the same time developing his organism, moulding his character, and enhancing his dramatic powers. These influences were exerted on him chiefly through the five closest friends he had in the city, five men intimately grouped, to be the confidant of one of whom was to be the confidant of all, men of the most remarkable force and finish of personality each in his own kind, each of them an intense type of the class he represented. They were all men of great personal beauty and strength, tall, supple, lithe, absolutely ignorant of fear, chivalrous in disposition, loose in habits, kind and loving in their native moods, but relentless and terrible in their wrath. Some insight into the sympathetic assimilation of these superb and fearful persons upon Forrest, and some tracing of the effect on his nature and on his art of the cycle of experience which they revealed to him partly by description, partly by personal introduction, are essential to an understanding of his great career. Those who are often and long together influence one another more than is usually supposed. Their giving and taking of opinions, prejudices, habits, and even organic peculiarities, are far beyond their own conscious purpose or recognition. Not unfrequently intimate associates obviously grow like one another in look, action, voice, passion, type of character, quality of temper, style of manners, and mode of life. This is confessedly matter of observation; but the law of its operation or the importance of the results very few understand. It is the sympathetic impartation and reproduction, between two or more parties, of inner states through outer signs; and, as to noble qualities, it is proportioned in degree to the docility of the persons, combined with their richness of organization. Those who have plastic nervous systems copiously furnished with force, and who are eager to improve, take possession of one another's knowledge and accomplishments with marvellous celerity. By intuition and instinct they seem to reflect their contents and transmit their habitudes with mutual appropriation. In this unpurposed but saturating school of real life what the superior knows and does passes into the sympathetic observer by a sort of contagion. Those whose nerves are capable of the same kinds and rates of vibration play into each other and are attuned together, as the sounding string of one musical instrument propagates its pulses through the air and awakens a harmonic sound in the corresponding string of another instrument. This is the scientific basis of what is loosely called _human magnetism_, and it is a factor of incomparable import in the problem of human life.