Vaillant also took lessons in anatomy with Joseph-Guichard Du Verney and chemistry with Antoine de Saint-Yon.

[3] Guy-Crescent Fagon, the king's physician and botanist, noticed Sébastien Vaillant and made him his secretary.

Fagon obtained from Louis XIV an authorization to build a "Cabinet of drugs" in the Royal Garden and charged Vaillant to furnish it and to provide security.

Charles Bouvard had the first greenhouse built: the Garden had plants from hot countries, and in 1714 Vaillant obtained the authorization to build another one.

He became ill and too poor to publish his Botanicon parisiensis (alphabetically or Enumeration of plants that grow in and around Paris) illustrated by Claude Aubriet.