«7 
Copper* 
per, except when cold. Those salts even which corrode 
that metal when left at rest in vessels, do not attack it in 
so sensible a manner when in a state of ebullition. 
Of all the preparations of copper by oxydation, there is 
none more valuable than that made by vinegar. All the 
verdigris used in commerce is prepared by that acid, and 
it is at Montpellier in particular and in the neighbourhood, 
that the manufactories of it are established. In the Me- 
moirs of the Academy of Paris for 1750 and 1 53, may- 
be seen a very exact description of the process then fol- 
lowed at Montpellier for making verdigris ; but as that 
process has been much improved, and as at present the 
husks of grapes are employed instead of the stalks, a me- 
thod far more economical, since wine is no longer used, 
the following account of the manner of manufacturing 
verdigris, as now practised, may be of utility to the pub- 
lic. 
The first materials used for this purpose are copper and 
the husks or skins of grapes left after the last pressing* 
The copper employed was formerly all imported from 
Sweden ; but at present it is brought from different foun- 
dries established at Saint Bel, Lyons, Avignon, Bedarieux, 
Montpellier, &c. It is in round plates half a line in thick- 
ness, and from twenty to twenty-five inches in diameter. 
Each plate at Montpellier is divided into twenty-five la- 
minae, forming almost all oblong squares of from four to 
six inches in length, three in breadth, and weighing about 
four ounces. They are beat separately with the hammer 
on an anvil to smooth their faces, and to give the copper 
the necessary consistence. Without this precaution it 
would exfoliate, and it would be more difficult to scrape 
the surface in order to detach the oxydated crust. Besides 
this, scales of pure metal would be taken off, which would 
hasten the consumption of the copper. 
The husks of grapes, known at Montpellier under the 
? H 
