As Midsummer's Eve approaches, the ability to glimpse the Faeries is heightened. The following "receipt" is dated 1600 :
To enable one to see Faeries :
A pint of sallet oyle and put it into a vial glasse; and first wash it with rose water and marygolde water; the flowers to be gathered towards the east. Wash it til the oyle becomes white, then put into the glasse, and then put thereto the budds of hollyhocke, the flowers of marygolde, the flowers or tops of wild thyme, the budds of young hazle, and the thyme must be gathered neare the side of a hill where the faeries used to be; and take the grasse of a faery throne; then all these put into the oyle in the glasse and settle it to dissolve three dayes in the sunne and then keep it for thy use. (mischievous giggle*)
* To make the oil to see the Faeries, you have to know where the faeries are.