Webster’s Revised Unabridged Dictionary · 1913
Preservative
Pre·serv′a·tive (prē·zẽrv′ȧ·tĭv), a. [Cf. F. préservatif.] Having the power or quality of preserving; tending to preserve, or to keep from injury, decay, etc.
Pre·serv′a·tive, n. That which preserves, or has the power of preserving; a presevative agent.
To wear tablets as preservatives against the plague. Bacon.