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MINIUM. “Lead(II,IV) oxide, also called red lead or minium, is the inorganic compound with the formula Pb3O4. A bright red or orange solid, it is used as pigment, in the manufacture of batteries, and rustproof primer paints. It is an example of a mixed valence compound, being composed of both Pb(II) and Pb(IV) in the ratio of two to one.” https://lnkd.in/d9WpCnR View in LinkedIn

RED LEAD. “Minium, also known as red lead, is a bright orange red pigment that was widely used in the Middle Ages for the decoration of manuscripts and for painting. It was made by roasting white lead pigment in the air; the white lead would gradually turn yellow, then into an orange lead tetroxide. The color varied depending upon how long the mineral was roasted. Minium of red lead was sometimes called stupium in classical Latin.” https://lnkd.in/dYDtahT) View in LinkedIn

MAKING RED LEAD. “Grind flake-white (note: lead oxide) on a stone without water, then put it in two or three new pots and place it over a burning fire. You have a slender curved iron rod, fitted at one end with a wooden handle and broad at the top, and with this you can stir and mix this flake-white from time to time. You do this for a long time until the red lead becomes completely red.” https://lnkd.in/d7yzXt5 View in LinkedIn

FRAGMENT FROM NATURE continues from last weekend and concludes this weekend on a mediaeval text about the practiced crafts of the day, including the diverse ranges of metallurgy, glassmaking including windows, and painting, particularly making paints, primers, glues and varnishes. It gives a remarkable insight into the resourceful and self-sufficient trades who had to make everything that they needed from scratch, sometimes planning a season ahead to get necessary plants in early spring. In particular, the toxic exposures they endured were unthinkable today, View in LinkedIn

“The words of the prophets are written on the subway walls”. View in LinkedIn

600 MILE WIDE PLASMA VORTEX RAING ELECTRONS. “What they found was something truly awe-inspiring: an anticlockwise spinning vortex that spewed electrons down at our planet’s upper atmosphere for eight long hours.” All at the North Pole. https://lnkd.in/g9DjNaP View in LinkedIn

STICKY VARNISH. “Put some linseed oil in a small new pot and add some finely powdered gum called sandarac, which the Romans call glassa. When you place it over a fire, heat it carefully, without letting it boil, until a third part has evaporated, and be careful of the flame because it is extremely dangerous and difficult to extinguish if it catches fire. Every painting coated with this varnish becomes bright and decorative and completely durable.” https://lnkd.in/d7yzXt5 View in LinkedIn