His thrift as well as intellectual determination paid off in 1836 when, at the age of 23, he entered a classroom for the first time. Having saved money from his wages over the years, while mastering the arts and sciences, he enrolled at the then Anderson University, Glasgow, for medical studies.
In 1838, he suspended his studies for a year to work for the London Missionary Society (LMS), who thereafter sponsored him to become a medical missionary.