The original goes: "pure vero et sancte servabo vitam meam et artem meam."
Borrowed from: http://www1.umn.edu/phrm/oaths/oath2.html
The English translation is not exactly loyal to the Latin. I would translate this more strictly as "in truth, purely and sacredly will I guard my life and my art."
Though the Hippocratic Oath may have originally been written in Ancient Greek
flebile nescio quid queritur lyra, flebile lingua murmurat exanimis, respondent flebile ripae