164 Mr. Richard Phillips on the (Serr. 
examine whether common verdigris consists entirely of it, or is 
a mixture of different compounds. 
For this purpose, I reduced 100 parts of French common ver- 
digris to powder, and boiled it with excess of lime, filtered the 
solution, passed carbonic acid through it, decomposed it by car- 
bonate of soda, and collected the carbonate of lime in the mode 
already described. The mean of two experiments carefully 
performed gave 29°3 of carbonate of lime, equivalent to a like 
quantity of acetic acid. 
The quantity of oxide of copper was ascertained by boiling 
100 parts of the verdigris in dilute sulphuric acid. Two parts of 
insoluble impurity were left, and the sulphate of copper being 
decomposed by heating with excess of potash, gave 43:5 of per- 
oxide of copper. This experiment was repeated without any 
Hie eae The composition of French verdigris is, therefere, as 
ollows : 
Acetic acid. ...... SIRS . 2, Me 29°3 
Peroxide of coppet®. Y9d4 0): OE 43°5 
Water? bow o eaek ve: SPORES bs 25:2 
Insoluble EGELSL: Sg eee SS - 2:0 
100°0 
‘That this is the true composition of common verdigris, and 
that it is essentially composed of the crystals which I have 
already described, was further proved by subjecting the verdigris 
manufactured by Mr. Badams, and in its compressed state, to a 
similar examination. This I found to consist of 
WAGE MCAT M6 OUP. A, J 20-48 
Peroxide of Copper Vs). a AY 44°25 
Waterey e2ren PRM art 720, 2A 
Insoluble matter ...... a aC OL 0°62 
100-00 
The action of water upon both these specimens of verdigris is 
perfectly similar to that upon the blue crystals of acetate of 
copper; indeed, from the following comparative statement, it will 
appear, except in containing less water, occasioned by artificial 
drying, that when deprived of insoluble matter, the three sub- 
stances resemble each other as perfectly as could be expected. 
Blue crystals, French verdigris. bags > He i 
Acetic acid. ........ 28°30 oe wee 29'S .wenes 29°62 
Peroxide of copper 43°25 ...... 93°D eevee 4429 
Water, ...sinisrpinins) sys QOrAD * opi e'g are 20'S. ome ge 25°51 
DE DUE Yi ve dems ms poy 0 Os nigeeiss > On 2, eo 
100-00 100-0 100-00 
Te — SE 
ST Sy a 
eo 
