Faithful Brothers, writings

Bacon. They are just such mixtures of general information about chemical substances and chemical philosophy as are found in the writings of the Faithful Brothers.42 References to some of their works will be met in the consideration of the thirteenth century encyclopedists. 

Chemistry in the tenth century writings of the Ichwan el safd—the Lautem Brueder or Faithful Brothers. ... 

This description of the nature of the metals gives evidence of familiarity with some properties of the metals, and their behavior. In general it differs but little except in minor details from the account of the origin of metals and their properties in the Arabian writings of the Faithful Brothers of the tenth century.2 Particular facts as to metals recorded in this treatise were, however, known to the ancients. 

The notion of the origin of the metals from quicksilver and sulphur was also in the writings of the Faithful Brothers supplemented by the theory of the origin of quicksilver from water and earth, and of sulphur from aerial or oily elements with earth. Vincent quotes from the De Aluminibus et Salibus attributed to Rhazes with respect to this theory.30... 

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