Making and Knowing
A minimal edition of BnF Ms Fr 640 in English Translation

- - - - - folio image: 083r - - - - -

Sand for lead

Recipe: Take grey soot from the silversmiths’ furnace, quick lime, and flour. Moisten according to [the rules of] the art, in the finest possible way you can.

at left top margin of folio 083r

The locksmiths’ grey soot which is held in their forge is quite fine when ground. It molds and is removed very neatly.