Cashel Byron's Profession by George Bernard Shaw

Cashel's pupils frequently requested him to hit them hard -- not to play with them -- to accustom them to regular, right down, severe hitting, and no nonsense. He only pretended to comply; for he knew that a black eye or loosened tooth would be immoderately boasted of if received in combat with a famous pugilist, and that the sufferer's friends would make private notes to avoid so rough a professor. But when Miss Carew's note reached him he made an exception to his practice in this respect. A young guardsman, whose lesson began shortly after the post arrived, remarked that Cashel was unusually distraught. He therefore exhorted his instructor to wake up and pitch into him in earnest. Immediately he received a blow in the epigastrium that stretched him almost insensible on the floor.

Rising with his complexion considerably whitened, he recollected an appointment which would prevent him from finishing his lesson, and withdrew, declaring in a somewhat shaky voice that that was the sort of bout he really enjoyed.