Green’s Dictionary of Slang

1. a translation, a ‘crib’.

1855		Yale College Songs in Hall (1856) 32: ’Twas plenty of skin with a good deal of Bohn.
1856		B.H. Hall College Words (rev. edn) 32: bohn. a translation; a pony. The volumes of Bohn’s Classical Library are in such general use among undergraduates in American colleges, that Bohn has come to be a common name for a translation.
1881-2		T.B. Reed Fifth Form at St Dominic’s (1890) 72: In the same desk were one or two books written by a man called Bohn; they seemed queer books, for they had Latin and Greek names outside, but all the reading inside was English.

2. a studious person; thus as v., bohn, to work hard.

1900

E.H. Babbitt ‘College Words and Phrases’ in DN II:i 24: bohn, n. 1. A close student. 2. One who uses a literal translation. [...] v. t. To study hard or diligently.