"With respect to all these, the best direction that can be given is to fix on some periods or epochas, which, by being often mentioned and thought of, explained and referred to, will at last be so deeply engraven on the memory, that they will be ready to present themselves whenever you call for them."
Letters on the Improvement of the Mind, Addressed to a Lady
At least 32 entries in ESTC (1773, 1774, 1775, 1777, 1778, 1783, 1786, 1787, 1790, 1793, 1797, 1800).<br> 
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See Hester Chapone, <u>Letters on the Improvement of the Mind, Addressed to a Lady</u>, 2 vols. (London: Printed by H. Hughs for J. Walter, 1773). &lt;<a href="http://find.galegroup.com/ecco/infomark.do?&contentSet=ECCOArticles&type=multipage&tabID=T001&prodId=ECCO&docId=CW114742139&source=gale&userGroupName=viva_uva&version=1.0&docLevel=FASCIMILE">Link to ECCO</a>&gt; &lt;<a href="http://books.google.com/books?id=_a1bAAAAQAAJ">Vol. 1 in Google Books</a>&gt;&lt;<a href="http://www.gutenberg.org/files/35890/35890-h/35890-h.htm">Project Gutenberg Edition</a>&gt;