14 
Arthur Aik in, Esq. on a scries of 
structure, and sometimes possessed of magnetic polarity, or into 
crystallized oxide, the latter being manifestly, in many cases at least, 
produced by sublimation, thus shewing the volatility either of iron 
or of its oxide, at a much lower temperature than has ever before, 
I believe, been observed. 
The other metals contained in this collection, namely, copper and 
lead, offer but few circumstances worthy of remark. 
No. 19* is a heap of copper coins, the legends on some of which 
are still very visible. These pieces are cemented together by 
crystalline red oxide of copper, so that a section of the mass would 
present an alternation of thin laminas of metallic copper and of red 
oxide. The metallic portion appears to be softer than ordinary 
copper, and presents no traces of crystalline structure. 
Nos. 20* 21, 22, are specimens of copper now converted into red 
oxide, mixed with green and blue carbonate. 
Nos. 23 and 24 are specimens of copper converted into semi- 
transparent red oxide, with more or less of an external crystalline 
form. 
No. 25 is a small bell, the figure of which is but little altered ; 
it is, however, entirely converted into alternate layers of red oxide 
of copper, and of white oxide, probably of tin. 
No. 26 is a mass of common pins, retaining much of their 
original figure, but rifted longitudinally. The structure of each 
pin has become concentric, like a stalactite, and the surface is 
covered with extremely minute crystals, which I consider as red 
oxide of copper. 
No. 27 is metallic lead, the surface being more or less oxidated. 
Mixed with the lead, and partly separated from it, are little crystal- 
line masses, with rectangular joints, that have all the external 
characters of galena. This galena, I am inclined to consider, not 
