Month: September 2022

CASEIN GLUE for making altar panels and doors. “Soft cheese is cut up into small pieces and washed with warm water with a pestle and mortar until the water, which you have poured in several times, comes out unclouded. Then this cheese is thinned out by hand and placed in cold water until it becomes hard...mixed with quicklime until it becomes thick as lees.” (Quicklime is roasted limestone, calcium oxide (CaO) which the craftsman would roast in a special kiln after quarrying the stone), https://lnkd.in/d7yzXt5 View in LinkedIn

ROASTED GYPSUM OR ALABASTER is CaSO4·2H2O + heat --> CaSO4.1/2 H2O (plaster of Paris). In mediaeval England there were extensive mines at Nottingham that was the source of an extraordinary alabaster used in church figures all over Europe that had the quality of ivory.” It was not commonly found throughout the UK, and limited to selected areas. https://lnkd.in/dvgrkJ7 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

THE FEEL OF AN ELECTRON. “Fundamental particles such as protons, neutrons, and electrons do not “look” or “feel” like anything at all, because “looking” and “feeling” are only meaningful for much larger objects. Those concepts have no meaning at the atomic scale.” https://lnkd.in/dpY5DrU View in LinkedIn

There are over twenty types of common wild flowers in blossom right now around Girona. View in LinkedIn

GOLD LEAF PREPARATION. “Take some Greek parchment, which is made up from linen rags, and rub it on each side with the red colour obtained by burning finely ground and dried ochre. Polish it very carefully with the tooth of a beaver, a bear, or a wild boar, until it shines and the colour adheres to it with the friction...” (etc). https://lnkd.in/d7yzXt5 View in LinkedIn

TINFOIL PREPARATION. “Beat pure tin very thin...rub it with cloth and charcoal...and a boar’s tooth until it shines. Get some switches of green wood, which you cut in April, split them down the middle and dry them over smoke. Then remove the outer bark and scrape the inside, which is yellow, into a clean pan adding a fifth part saffron. Over this pour plenty of old wine or beer, and when it has stood overnight, heat it in the morning over a fire until it is lukewarm...” (etc). https://lnkd.in/d7yzXt5 View in LinkedIn

GRINDING COLORS INTO SAP GREEN. “Take the gum which oozes from the cherry or plumb tree, cut it up very small, and place it in an earthenware pot. Pour in plenty of water, and place it in the sun, or in the winter over a fire until the gum melts. Then strain it through a cloth and, with this (drying) medium, grind the colours.” https://lnkd.in/d7yzXt5 View in LinkedIn

GLUE FOR BINDING GOLD TO BOOKS. “Take the bladder of a fish, known as the sturgeon, wash it three times in lukewarm water, cut it up into pieces and, putting it in a very small pot with water, allow it to soften overnight. In the morning...test the glue.” https://lnkd.in/d7yzXt5 View in LinkedIn

ALTERNATIVE GLUE FOR GOLD PLATING. “Heat the bladder of an eel, which has been carefully scraped and washed. You can also heat three times the bones of the head of a dried pike...add a third part of transparent glue and heat gently.” https://lnkd.in/d7yzXt5 View in LinkedIn