Parting, Cementing and Colouring -
Formulae of a "Warden" from the Rhine Region from around 1450
The historical archives of the city of Cologne contain a manuscript of 48 pages carefully written in Lower Rhine dialect in about 1450 by a "warden" who had a good knowledge of both metallurgy and minting and recorded all the information he had collected. These wardens were chemists working in mines, foundries, mints and also as officials for checking the fineness of traded precious metals and articles made from them. The title stems from the French word "gardien" and, coming via north French "wardien" and Dutch "wardijn", entered German as "Wardein" and replaced the German terms of Probierer, Huter and Aufzieher. In the case of minting, the occupations of assayer, i.e. precious metals expert, and keeper of the mint die were merged and extended to monitoring and producing weights. Wardens had a sound knowledge of metallurgy, were often goldsmiths or mining and foundry experts and also had to handle the parting of gold-silver alloys.
The manuscript, though not divided into sections, basically has two parts. First, the unknown author coming from the Lower Rhine region deals with questions concerning minting and metrology in the period around 1450, going far beyond the Rhine region. Second, he provides a collection of metallurgical formulae. Apart from the part concerning the history of coinage and metrology, the manuscript primarily deals with the formulae which were presumably collected over many years.