MOULD(?).
The mould (?) may be of Venus, or of Jupiter and Saturn and placed frequently in the fire. And it should be worked with fine emery and the mould (?) should be of Venus and Jupiter impasted over (?) Venus. But first you will test Venus and Mercury mixed with Jove, and take means to cause Mercury to disperse; and then fold them well together so that Venus or Jupiter be connected as thinly as possible.
[Footnote: See the note to 637.]
Taken from The Notebooks of Leonardo da Vinci edited by Jean Paul Richter, 1880.