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THEOPHILUS WAS A CRAFTSMAN. “He mentions that he has gained experience of the methods that he is about to describe, having “examined them individually with careful trial and proved them all with hand and eye.” https://lnkd.in/d7yzXt5 View in LinkedIn

MAKING FLAKE-WHITE. “Get some sheets of lead beaten out thin, place then to dry, in a hollow piece of wood, and pour in some warm vinegar or urine to cover them. Then, after a month, take off the cover, and remove whatever white there is.” (Lead oxide), https://lnkd.in/d7yzXt5 View in LinkedIn

IMPLICIT CHEMISTRY. In the middle ages, chemistry as such did not exist, but it was ingeniously practiced empirically by craftsmen. It is rather easy, today, to read his recipes and deduce the chemical reactions that were being undertaken. Like the ingenuity of cooking methods worldwide, artisanal workers came upon extraordinary solutions to their undertakings. I call it the distributed genius spread over generations of trial and error. https://lnkd.in/d7yzXt5 View in LinkedIn

MAKING SALT GREEN. “Next, gather some twigs, place them in the hollow box so that two parts of the cavity are below and one part above, coat the copper sheets on each side with pure honey over which you sprinkle pounded salt...pour warm vinegar or hot urine until a third part of it is filled. You should place this wooden container in a place where you can cover it on every side with dung. After four weeks take off the cover and whatever you find on the copper scrape off and keep.” (ie: approximately sodium chloride plus copper in acid makes copper chloride CuCl2). https://lnkd.in/d7yzXt5 View in LinkedIn

MAKING FOLIUM FROM ROASTED ASHES. “...when they have been white hot for a very long time, and after they have cooled, put some of them in an earthenware pot, pour in some urine and stir with a piece of wood. When the preparation has settled and become clear, pour on sone red folium, lightly grind it on a stone and add to it a fourth part of quicklime.” (Etc). https://lnkd.in/d7yzXt5 View in LinkedIn

BOOK COLORS. “Salt Green is of no use for a book. Spanish Green you mix with pure wine, and, if you wish to make shadows, add a little of the juice of the iris, cabbage or leek. Red lead, flake-white and vermillion you mix with the white of an egg.” https://lnkd.in/d7yzXt5 View in LinkedIn

DRAPERY COLORS. “On this colour when it is dry, a thin glaze of azure blue, mixed with the yolk of an egg which has been diluted with a lot of water, is spread, and in top of this again a thicker glaze to enhance its beauty. “ https://lnkd.in/dh4ZPzF View in LinkedIn

THE FIRST ROSE COLOR. “Mix with the plain flesh colour a little vermillion and a little red lead.” https://lnkd.in/d7yzXt5 View in LinkedIn

ON THE MIXING OF FLESH COLORS. “Take flake-white -- which is white made from lead -- and, without grinding it, out it just as it is, dry, into a copper or iron pot, place it over a fire and heat it until it has changed to a yellow colour. Then grind it and mix it with some ordinary flake-white and vermillion until it becomes the colour of flesh.” https://lnkd.in/d7yzXt5 View in LinkedIn

VERMILLION. “Take some sulphur of which there are three kinds -- white, black, and yellow. Break it up on a dry stone, and add to it two parts of quicksilver, weighing them on the scales...put them in a glass jar, stop up the mouth so that no vapour can escape, and put it on a fire to dry. Then place it on a burning fire, and, when it begins to get hot, you will hear a crackling noise inside caused by the quicksilver combining with the burning sulphur. When the noise has stopped, remove the jar at once, open it and take the colour.” (ie: S + Hg --> HgS, a toxic process to say the least.) https://lnkd.in/d7yzXt5 View in LinkedIn