languages, and the careful and repeated perusal of the best authors
in both.

His third winter-sessions at Edinburgh having passed away, he was
induced to go out and seek his fortune in Jamaica, and accordingly
proceeded thither in a vessel commanded by one Captain Cunningham,
who had previously been employed as master of a transport at the
siege of Havannah. It is far from improbable that it was from his
conversations with this individual that Jackson derived those hints,
of which at a future time he availed himself, respecting the
transmission of troops by sea without injury to their health; but it
is quite certain his conviction of the enormous value of cold-water
affusions as a curative agent in the last stage of febrile
affections, was imbibed from this source.

Arriving in Jamaica, he in 1774 became assistant to an eminent
general practitioner at Savana-la-Mar, Dr King, who was also in
medical charge of a detachment of the first battalion of the 60th
regiment. This latter he consigned to Jackson's care; and well
worthy of the trust did our young adventurer, though but twenty-four
years of age, approve himself--visiting three or four times a day
the quarters of the troops to detect incipient disease, and studying
with ardour and intelligent attention the varied phenomena of
tropical maladies. Four years thus passed profitably away, and they
would have been as pleasant as profitable, but for one circumstance.
The existence of slavery and its concomitant horrors appears to have
made a deep impression on Jackson's mind, and, at last, to have
produced in him such sentiments of disgust and abhorrence, that he
resolved on quitting the island altogether, and, as the phrase is,
trying his luck in North America, where the revolutionary war was