It comes from Ariel's song in The Tempest. " Full fathom five thy father lies, / Of his bones are coral made, / Those are pearls that were his eyes: / Nothing of him that doth fade, / But doth suffer a sea-change / Into something rich and strange."
It is available on DVD but most copies are poor quality bootlegs. For good quality licensed and restored releases, search for the "Alfred Hitchcock Collectors' Guide".