ANNALS 
OF 
PHILOSOPHY. 
- SEPTEMBER, 1822, 
ARTICLE I : 
On the Composition of Common Verdigris. 
By Richard Phillips, FRS, L. & E. &c. 
_...In the Annals of Philosophy, vol. i. p. 417 (New Series), I. 
gave an analysis of crystallized verdigris, sometimes, but impro- 
perly, called distilled verdigris. From the experiments which E 
detailed, it appears to be a compound of two atoms of acetic 
acid, one of peroxide of copper, and three of water; or in other 
a words, of one atom of binacetate of copper combined with three 
atoms of water of crystallization. 
: Soon after I had completed that analysis, I began an exami- 
nation of common verdigris, usually termed subacetate of copper, 
but some difficulties occurred which induced me to discontinue 
the experiments. It is well known that when a small quantity 
of water is added to a fragment of common verdigris, it softens 
__ and swells by imbibing the water, and if more be added, a blue 
solution is obtained, while a portion of the verdigris remains 
undissolved. 
It appeared to me at first probable that common. verdigris 
might be a mixture of binacetate and subacetate of copper; the 
former dissolving and forming the blue solution, and the latter 
remaining undissolved. Upon examination, however, I could 
not find this to be the case, and one circumstance appeared 
unfavourable to such a supposition. When the verdigris in 
question is closely.examined, it is found to contain small crys- 
tals, which, instead of being distinctly formed, and of a green 
| «colour, as is the case with the binacetate, are acicular, of alight 
__ blue colour and silky lustre. 
_*. New, Series, vow. tv. M 
