1Q2 TRAVELS THROUGH 



is the fame as in the before-mentioned Floren^ 

 tine Mofaic work. I have feen a Mofaic portrait 

 of the prefent Emperor, which was highly refem- 

 bling him -, and a great many artiils are employed 

 to decorate St. Peter's with fuch immortal unde- 

 caying pictures. They have improved the art 

 of the ancients, and attempted coloured baftb 

 relievi. 



In the villa Adrian! at Tivoli, near Frafcati, 

 and in other places, have been found the noblelt 

 ancient monuments of that kind. I obferved in 

 them blue frittas, which proved to me that the 

 ancients knew the ufe of cobalt and the prepara- 

 tion of fmalt *. The fineft red fritta, refembling 

 fealing wax, is but a copper-fcoria, whofe compo- 

 fition was an arcanum of a certain Mr. Matthioli 

 at Rome. Though they imitate it, they do not 

 arrive to the fame brightnefs of colour. 



The cabinet which Mercati defcribed in the 

 Metallotheca Vaticana has difappeared. 



The Mufeum Kircherianum, in the Collegia Ro- 

 under the direction of the Jefuits, has been 



* They had it, perhaps, as many other mechanical arts, 

 from the Egyptians. At leaft the Egyptians employed fmalt 

 or vitrified cobalt in their paintings and pottery, as plainly 

 appears -on the painted Mummy-chefts, and in feveral fmall 

 sauhen figures, kept in the Bmilh Mufeum, 



defcribed 



