ANCIENT AND MEDIJEVAL CHEMISTRY. 113 



demonstrate here this correlation, which nobody has till now 

 pointed out. 



It is known that the receipts of therapeutics and materia medica 

 have been preserved in a parallel way by practice, which has never 

 ceased, in the Receptaries and other Latin treatises ; these trea- 

 tises, translated from the Greek during the period of the Roman 

 Empire, and compiled in the first and second centuries, passed 

 from hand to hand, and were copied frequently during the earlier 

 portions of the middle ages. The transmission of the military arts 

 and of fire-producing formulas, particularly, was carried on from 

 the Greeks and Romans through the barbarous ages. In short, 

 the necessity of the applications has always caused the subsist- 

 ence of a certain experimental tradition of the arts of ancient 

 civilization. 



The oldest technical treatises in Latin of the middle ages on 

 subjects in chemistry with which we are acquainted are the 

 Formulas for Dyeing (Compositiones ad tingendo), of which we 

 have a manuscript written toward the end of the eighth century, 

 and the Key to Painting {MajypcB clavicula), the oldest manuscript 

 of which is of the tenth century. The Formulas for Dyeing is 

 not a methodical work, but a book of receipts and documents col- 

 lected by a dyer for use in his art and intended to furnish him 

 with working processes and information concerning the origin 

 of his prime materials. It concerns such subjects as the color- 

 ing or dyeing of artificial stones for mosaic work ; gilding and 

 silvering and polishing them ; making of colored glass in green, 

 milky white, various shades of red, purple, yellow the colors 

 being both deep and superficial, and often brought out by the aid 

 of simple varnishes ; coloring of skins in purple, green, yellow, 

 and various reds ; dyeing of woods, bones, and horns ; notices of 

 minerals, metals, and earths used in goldsmiths' work and paint- 

 ing. Curious ideas are set forth on the function of the sun and 

 of heat, peculiar to certain warm earths in the production of 

 minerals endowed with corresponding virtues ; while a cold earth 

 produces minerals of weak quality. This reminds us of the the- 

 ories of Aristotle on dry exhalation as opposed to moist ex- 

 halation in the generation of minerals theories that made an 

 important figure in the middle ages. The author distinguishes a 

 feminine and light lead mineral as against a masculine and heavy 

 mineral ; a distinction like that mentioned by Pliny between 

 male and female antimony, the male and female blue of Theo- 

 phrastus, and many others. Minerals were continually likened 

 in the chemistry of the middle ages to living beings. 



We read likewise in this work of articles developed in certain 

 operations, such as the extraction of mercury, lead, the roasting 

 of sulphur, preparations of white lead with lead and vinegar, of 



VOL. XLV. 9 



