148 The Process followed at Montpellier in 
rner position, and left there for seven or eight days ; after 
which they are once or twice immersed again. This im- 
mersion and drying are renewed six or eight times, every 
seven or eight days. As the plates formerly were put 
into wine, these immersions were called one wine , two 
wines , three wines , according to the number of times. 
By this process the plates swell up, the green is nourish- 
ed, and a coat of verdigrise is formed on all their sur- 
faces, which may be easily detached by scraping them 
with a knife. 
Each jar furnishes five or six pounds of verdigrise at 
each operation. It is then called fresh verdigrise, moist 
verdigrise, &c. This verdigrise is sold in that state by 
the manufacturers to people who dry it for foreign expor- 
tation. In this first state it is only a paste, which is 
carefully pounded in large wooden troughs, and then put 
into bags of white leather, a foot in height and ten inches 
in diameter. These bags are exposed to the air or the 
sun, and are left in that state till the verdigrise has 
acquired the proper degree of dryness. By this opera- 
tion it decreases about fifty per cent, more or less ac- 
cording to its primitive state. It is said to stand proof 
by the knife, when the point of that instrument pushed 
against a cake of verdigrise through the skin cannot pene-, 
irate it. 
The plates of copper which have been already used 
are again employed for the same operation, till they are 
almost completely consumed. Instead of heating them 
artificially, as above mentioned, they are sometimes ex- 
posed only to the sun. The same plates will serve some- 
times for ten years, but they are often worn out in two 
or three. This, however, depends on the quality of the 
copper. That which is extremely smooth, well beat, and 
very compact, is always most esteemed* 
