"That vibrations [in the air above London] which are nearly isochronous affect and modify one another, so as to become perfectly so, sufficiently corresponds to the phænomena of ideas, and therefore makes no objection to this doctrine."
Hartley's Theory of the Human Mind, on the Principle of the Association of Ideas; with Essays Relating to the Subject of It
At least 4 entries in ECCO and ESTC (1775, 1776, 1790).<br>
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See <u>Hartley’s Theory of the Human Mind, on the Principle of the Association of Ideas; With Essays Relating to the Subject of It. By Joseph Priestley, LL. D. F. R. S.</u> (London: Printed for J. Johnson, No. 72, St. Paul’s Church-Yard, 1775). &lt;<a href="http://estc.bl.uk/T141560">Link to ESTC</a>&gt;