368 Rev. Mr. Conybeare on Works in Niello, and the [Nov, 
artist, G. B. Palori, who invented a new species of moulds for 
casting in plaister, by covering the original statue with a mask 
of paper, or rather papier machae (carta pasta) and linen, stratum 
superstratum. When this was sufficiently thick and hard, it 
was cut from the statue in convenient portions ; then reunited, 
strengthened by the addition of fresh matter, and rendered 
impermeable to water by wax and asphaltum (péce greca). 
The moulds thus produced, were light, portable, unexpensive, 
not liable to break, and well adapted for their object. C., del 
Arte Alchimica, and C. del Arte Distillatoria. In the former of 
these, he again attacks the alchemists as to the probable attain- 
ment of their object, but allows that in their researches they 
frequently made discoveries of great interest and value. The 
latter contains nothing which at the present day could inform or 
interest the chemical reader. 
C. Del Arte del Fabro Orefice. Besides the article already 
quoted on the Niello, contains directions for soldering, tempering, 
and. colouring gold, and for enamelling, but nothing on the 
composition of the enamels or pastes themselves. C. del Arte 
del Fabro Ramario. Mentions the art of tinning copper vessels. 
C. del Arte del Fabro Ferrario. Treats of the manufactory and 
tempering of steel, of colouring, engraving, and damasquining 
its surface; these arts he terms secrets. Among other of these 
secrets is one for rendering iron soft, and tractable as lead; a 
process which must have been in request at a period which, 
among other works of art, produced many beautiful specimens 
of chasing in iron. It consists in exposing to the continued 
heat of a furnace the iron first anointed with 02/ of bitter almonds, 
and then coated with a paste made of wax, assa fatida, and a 
small quantity of alkali, covering the whole with a strong lute. 
C. del Arte del Fabro Stagnario. The composition for printer’s 
types, he states to be six parts of fine tin, one of lead, and one 
of antimony, ( 
In subsequent chapters, he describes the process of recover- 
ing gold and silver from plated articles, or mineral compounds, 
ly amalgamation with mercury. For this secret he states himself 
to have given a diamond ring worth 25 ducats. 
A more interesting chapter is that on the “ Pratica et Modo 
di fare li Specchi di Metallo.” He mentions a tradition as to 
the existence of telescopic specula, as far back, if I understand 
him, as the age of Augustus. ‘‘ Che mostrano imagine delle 
cose lontane et non delle propinque.” He treats also of burning 
specula, of one especially belonging to a German, by which gold 
was kept in a state of fusion. He mentions another (telescopic ¢) 
speculum, said to have existed at Tunis. “ Il quale era tanto 
lucido, che del piu alto della Rocca voltan dolo verso il Porto 
della Goleta vi si discernava tutti le navi che varano surte, et 
tutte le genti che arano con esse, et de che colori et habiti eran 
vestiti: certo credo che fusse con questi trovata la prospettiva 
