ORIGINAL AIRDATE: May 21st, 1992 ---
MacGyver returns for one last Phoenix mission, recovering Jack Dalton's body, dead or alive.
MISSION: MacGyver follows Jack to a remote location rumored by locals as home to the fountain of youth. Unfortunately, a nearby military installment threatens the miraculous spring.
This week's highlights include:

Heavy water (Chemistry)

Heavy water (deuterium oxide (2H2O)) is a form of water that contains a larger than normal amount of the hydrogen isotope deuterium (2H or D, also known as heavy hydrogen), rather than the common hydrogen-1 isotope (1H or H, also called protium) that makes up most of the hydrogen in normal water.

Check out the article on wikipedia: https://en.wikipedia.org/wiki/Heavy_water.

Watch S7E14: "The Mountain of Youth" on CBS's website or check the alternative streamability of this episode here.