"Now, if we consider the human mind, we shall find that with regard to the passions, it is not of the nature of a wind instrument of music, which, in running over all the notes, immediately loses the sound after the breath ceases; but rather resembles a string-instrument, where, after each stroke, the vibrations still retain some sound, which gradually and insensibly decays."
— Hume, David (1711-1776)
(II.iii.9, p. 282 in OUP ed.)
David Hume, A Treatise of Human Nature. Being an Attempt to Introduce the Experimental Method of Reasoning into Moral Subjects. 3 vols. (London: Printed for John Noon, 1739; Thomas Longman, 1740). <Link to ESTC><Link to ECCO><Link to ECCO-TCP><Link to OLL>
Reading David Hume, A Treatise of Human Nature, eds. D. F. and M. J. Norton (Oxford: OUP, 2000). Searching in Past Masters and OLL editions.