BOOK XXXlIi. XIX. 62-xxi. 66 



into thread and woven into a fabric like wool, even 

 without an addition of wool. Verrius informs us 

 that Tarquinius Priscus celebrated a triumph wearing Traduionai 

 a golden tunic. \Ve have in our own times seen the ^1^**!?^ 

 Emperor Claudius's wife Agrippina, at a show at 

 which he was exhibiting a naval battle, seated at 

 his side wearing a mihtary cloak made entirely of 

 cloth of gold. For a long period gold has been 

 woven into the fabric called cloth of Attahis," an 

 invention of Kings of Asia. 



XX. On marble and other materials incapable 

 of being raised to a Mhite heat gold is laid with M'hite 

 of egg ; on wood it is laid vrith glue according to a 

 formula ; it is called leucophorum, white-bearing ; 

 what this is and how it is made we will exph^in in its 

 proper place. The regular way to gild copper xxxv. 36. 

 would be to use natural or at all events artificial 

 quicksilver,^ concerning which a method of adultera- 



tion has been devised, as we shall relate in describing §§ 100. 125. 

 the nature of those substances. The copper is 

 first subjected to the violence of fire ; then, when 

 it is red hot, it is quenched with a mixture of brine, 

 vinegar, and alum,'^ and afterwards put to a test, its 

 brilliance of colour showing whether it has been 

 sufficiently heated ; then it is again dried in the fire, 

 so that, after a thorough poHshing with a mixture of 

 pumice and alum, it is able to take the gold-leaf 

 laid on with quicksilver. Alum has the same clean- § 60. 

 sing property here that we said is found in lead.^ 



XXI. Gold in our part of the workl — not to speak Methodsfor 

 of the Indian gold obtained from ants or the gold ^ow?'^""^ 

 dug up by griffins in Scythia «^ — is obtained in three 



*■ This Indian and Scythian gold was perhaps got from Tibet. 

 The stories about it go back to Herodotus. 



51 



