which the notes can be put is provided by Professor E. L. McAdam's _Dr.
Johnson and the English Law_ (1951) in which are recorded notes showing
Johnson's familiarity with various legal terms. Further insight into
Johnson's knowledge of books of _esoterica_, histories, ballads, etc.,
can be gleaned from the comments on Shakespeare. A subject in which I
must confess an interest possibly out of proportion to its worth is that
of Johnson's reading. Some day we will have a list, probably never
complete, of the books we can be sure Johnson knew. Not only will the
notes to Shakespeare supply the names of works that Johnson knew, quoted
from, or alluded to only in these notes, but they will also help to
establish more firmly certain fields or subjects that fascinated him.
Thus, one note is evidence for Johnson's knowledge of Guevara's _Dial of
Princes_; another for his familiarity with Ficino's _De Vita Libri
Tres_; and nowhere else in Johnson's works, letters, or conversation are
these works so much as alluded, to. Other notes show us that Johnson
remembered now a poem, now an essay, from the _Gentleman's Magazine_. In
still other notes one encounters or is able to identify the names of
John Caius, John Trevisa, Dr. William Alabaster, Paul Scarron, Abraham
Ortelius, Meric Casaubon, and many others. Plays, sermons, travel books,
ballads, romances, proverbs, poems, histories, biographies, essays,
letters, documents--all have their place in the notes to Shakespeare.

No discussion of Johnson's knowledge of books can ignore the importance
of his reading for the _Dictionary_. Nor can this same preparatory
reading be overlooked in a consideration of the Shakespeare edition.
Between one-fifth and one-fourth of the notes to Shakespeare can be
traced back to the _Dictionary_. What is more, the revision of the 1765
_Shakespeare_ was undertaken at the same time that Johnson was revising
his _Dictionary_; both revisions appeared in the same year. And so one
is not surprised to find that these two labors are of reciprocal