854 Experiments and Observations 



III. Of the Yellows of the Ajicienls. 



A large earthen pot found in one of the chambers of the I);iths 

 of Titus contains a quantity of a yellow paint, vvhith, suhniitted 

 to chemical esaniination, ])roved to be a mixture of yellow ochre 

 with chalk or carbonate of lime. 



This colour is used in considerable quantities in different parts 

 of the baths ; but principally in the least ornamented chainber-^, 

 and in those which were pro!)a])ly intended for the use of the 

 dn.nestics. In the. vase to which' I alluded in the last section, 

 I found three difrcrcnt yellows ; two of them proved to be yellow 

 ochres mixed with different quantities of chalk, and the third a 

 yellow ochre mixed with red oxide of lead, or minium. 



The ancients procured their yellow ochre* from different parts 

 of the world ; but the most esteemed, as we are informed by 

 Pliny, was the Athenian ochre ; and it is stated by Vitruvius, that 

 in his time the mine which produced tliis substance -was no 

 Ioni!;er worked. 



The ancients had two otlicr colours, which were orange or 

 yellow; the aiinpigmentiini^ or agT=vixoi/, said to approach to 

 gold in its colour, and which is described by \'itruvius f as found 

 native in Pontus, and which is evidently sulphuret of arsenic ; 

 and a pale sandarach, said by Pliny to liave been found in gold 

 and silver mines, and which was imitated at Rome by a partial 

 calcination of ceruse, and uhich must have been massicot, or 

 the yellow oxide of lead mixed with minium. That there was a 

 colour called by the Romans sandarach, different from pure 

 niiniurn, is evident from what Pliny says; namely, that the palest 

 kind of orpiment resembles sandarach, and from the line of 

 Naevius, one of the most ancient Latin poets, " Merula sanda- 

 racino ore:" so that this colour must have been a bright vellow 

 similar to that of the beak of the blackbird 4:. Dioscorides de- 

 ."-oribes tiie best (ra.v'6ag(x^-^ as approaching in colour to ver- 

 milion §, and the Greeks probably always applied this term to 

 minium ; but the Ron^.ans seem to have used it in a different 

 sense; and some confusion was natural when different colours 

 \Yere prepared from the same substance by different degrees of 

 calcination. 



I have not detected the use of orpiment in any of the ancient 

 fresco paintings ; hut a deep yellow approaching to orange, which 

 covered a piece of stucco in the ruins near the monument of 

 Caius Cestius, proved to be oxide of lead, and consisted of mas- 

 sicot mixed with minium. It is probable that the ancients used 

 many colours from lead of different tints between the usta of 



* «.'tf«>Theoplirastiis de Lafiifliljus. f Vitruvirsjib. vij. 



I lliitoire de in Pcintuic uncicnne, page 199. & Lib. v i^Q. 



Plinv. 



