The cause of it was over-application to your profession, and, perhaps, a life too bare of natural recreation and pleasures.
The requirements were certainly moderate, and our healths needed not to suffer from over-application.
early 15c., "the bringing of something to bear on something else," from Old French aplicacion (14c.), from Latin applicationem (nominative applicatio) "a joining to, an attaching oneself to," noun of action from past participle stem of applicare (see apply). Meaning "sincere hard effort" is from c.1600. Meaning "a formal request to be hired for a job or paid position" is by 1851.