Gold parting of the salt cementation process. This mixture is then added to an earthenware pot and layered with thin sheets of gold fold. The pot is then sealed and heated in a furnace. It was during the medieval period that distillation was discovered and the first description of nitric acid production was given by Pseudo-Geber in the "Summa perfectionis", 1330. Nitric acid is able to dissolve silver. The addition of sal ammoniac to nitric acid creates Aqua regia and this acid is able to dissolve gold. Both acids are used in the acid method of parting but the acids were expensive
Caftaric acid little to no caftaric acid. Grape reaction product (2-S glutathionyl caftaric acid) is an oxidation compound produced from caftaric acid and found in wine. Malvidin 3-glucoside alone is not oxidized in the presence of grape polyphenol oxidase (PPO), whereas it is degraded in the presence of a crude grape PPO extract and of caftaric acid, forming anthocyanidin-caftaric acid adducts. Caftaric acid Caftaric acid is a non-flavanoid phenolic compound. It is found in the juice of grapes ("Vitis vinifera") and impacts the color of white wine. It is an esterified phenolic acid, composed of caffeic acid, a hydroxycinnamate produced by plants,