The Da Vinci Notebooks at sacred-texts.com
On stucco (729. 730).Place stucco over the prominence of the..... which may be composed of Venus and Mercury, and lay it well over that prominence of the thickness of the side of a knife, made with the ruler and cover this with the bell of a still, and you will have again the moisture with which you applied the paste. The rest you may dry 351
well; afterwards fire it, and beat it or burnish it with a good burnisher, and make it thick towards the side.
Powder ... with borax and water to a paste, and make stucco of it, and then heat it so that it may dry, and then varnish it, with fire, so that it shines well.
19:351 : In this passage a few words have been written in a sort of cipher--that is to say backwards; as in l. 3 erenev for Venere, l. 4 oirucrem for Mercurio, l. 12 il orreve co ecarob for il everro (?) co borace. The meaning of the word before "di giesso" in l. 1 is unknown; and the sense, in which sagoma is used here and in other passages is obscure.-- Venere and Mercurio may mean 'marble' and 'lime', of which stucco is composed.
12. The meaning of orreve is unknown.