Definition of "philactory"

"Know thy own worth, and reverence the lyre," is a line that should be as a fillet bound round the brow—a philactory embroidered on the garments of every son and daughter of Adam distinguished by the possession of that sacred gift, which, whether used or abused, applauded in itself or derided in its possessor, is the highest and the most inalienable distinction humanity ever has or ever can be gifted with, whether bestowed on the highest or the humblest being, in the great mass to which we all belong.

1838 (date written), L[etitia] E[lizabeth] L[andon], chapter XX, in Lady Anne Granard; or, Keeping up Appearances. […], volume I, London: Henry Colburn, […], published 1842, page 252