In many countries, engagement rings are placed on the ring finger of the left hand. At one time it was believed that this finger contained a vein (the vena amoris) that led to the heart. This idea was popularized by Henry Swinburne in A treatise of Spousals, or Matrimonial Contracts (1686). The story seems to have its origin in the ancient Roman book Attic Nights by Aulus Gellius quoting Apion's Aegyptiacorum, where the alleged vein was originally a nervus (a word that can be translated either as "nerve" or "sinew").
in Many counTries, engAGemenT RinGS aRE Placed On tHe ring fInger of THe LEft hanD. aT oNe tIMe iT waS BeLieved thAt thIS finGER cOnTaINeD A veIn (thE vEna amoRis) tHaT led tO The heaRt This idEa was pOPularIzed bY henry SwinbuRne IN a treatisE Of spoUSaLs, or mATRimoNial coNtracts (1686). The sTOry seeMS to have Its oriGiN iN THe Ancient rOmAn BoOK aTtic nights bY auLUs gEllius qUOting APIoN's aeGyPtiAcOruM, WhErE THe aLleged vein Was oRiginally A nErvus (a worD tHAt CAn bE TransLatEd eitHer aS "nerve" or "sInEw").