The song of the nightingale is to be heard, without intermission, for fifteen days and nights, continuously, when the foliage is thickening, as it bursts from the bud; a bird which deserves our admiration in no slight degree. First of all, what a powerful voice it has in so small a body! its note, how long, and how well sustained! And then, too, it is the only bird the notes of which are modulated in accordance with the strict rules of musical science. At one moment, as it sustains its breath, it will prolong its note, and then at another, will vary it with different inflections; then, again, it will break into distinct chirrups, or pour forth an endless series of roulades. Then it will warble to itself, while taking breath, or disguise its voice in an instant; while sometimes, again, it will twitter to itself, now with a full note, now with a grave, now again sharp, now with a broken note, and now with a prolonged one. Sometimes, when it thinks fit, it will break out into quavers, and will run through, in succession, alto, tenor, and bass: in a word, in so tiny a throat is to be found all the melody that the ingenuity of man has ever discovered through the medium of the invention of the most exquisite flute: so, that there can be no doubt it was an infallible presage of his future sweetness as a poet, when one of these creatures perched and sang on the infant lips of the poet Stesichorus. No doubt there is a remarkable degree of art in its performances, for every individual has a number of notes peculiar to itself; they do not, all of them, have the same, but each, certain melodies of its own. They vie with one another, and the spirit with which they contend is evident to all. Often the one that is vanquished, dies in the contest, preferring to yield its life rather than its song. The younger birds are listening, in the mean time, and receive the lesson in song from which they are to profit. The learner hearkens with the greatest attention, and repeats what it has heard, and then they are silent by turns; this is understood to be the correction of an error on the part of the scholar, and a sort of reproof, as it were, on the part of the teacher. Nightingales bring as high a price as slaves, and sometimes more than used formerly to be paid for a man in a suit of armor.