Hermetic

Webster's Practical Dictionary- A Practical Dictionary of the Englih Language · 1884 · p. 190

her-mefik, -ical, a. Pert, to chemistry; chemical; pert, to that philosophy which pretends to explain all the phenomena of nature from chemical principles, salt, sulphur, and mercury pert, to the system which explains causes of diseases, etc., on the principles of the hermetical philosophy, esp. on the system of an alkali and acid; perfectly close, so that no air, gas, or spirit can escape.