54 
[Assembly 
The lead ashes, as it is commonly called, found in great abun- 
dance on that part of the Rossie vein which was exposed to the 
atmosphere, and which invests most of the surface specimens of 
galena, I ascertained upon analysis to be a mixture of carbonate 
and sulphate of lead and carbonate of lime, in variable proportions. 
The formation of this compound is undoubtedly due to the reac- 
tion of the carbonate of lime and sulphuret of lead, together with 
the free exposure to atmospheric influence. 
The only remaining mineral which 1 obtained from this locality, 
was iron pyrites, associated in small quantities with the galena. 
It is usually of a golden yellow colour, and sometimes occurs, as 
already stated, in the form of the cube with truncated angles. The 
limestone in this vicinity contains abundance of scales of graphite 
or plumbago, which has often been mistaken for galena. It may 
always be distinguished by the trace which it produces on paper. 
In several parts of this and the adjoining towns there are dis- 
tinct veins of semi-crystalline carbonate of lime, generally having 
an easterly and westerly direction, and containing galena in great- 
er or less quantities. These veins are usually indicated by the 
occurrence of small rounded masses of galena, covered with the 
lead ashes above described. Near De Long's mill is a vein of this 
kind, which is twelve or fifteen inches at the top of a ledge of rocks, 
and contains small masses of galena disseminated through it; but 
it gradually becomes narrower, and at the depth of 80 or 90 feet 
it is scarcely six inches in width, and has no appearance of being 
metalliferous. There is therefore, at present, nothing which would 
warrant further expenditure at this locality. 
In this vicinity I obtained a specimen of satin spar, some hand- 
some varieties of feldspar, and fine crystals of calcareous spar of a 
straw yellow color, and nearly transparent. 
Several veins of calcareous spar containing galena have been 
found in the same county, on the south-east side and near the head 
of Black Lake. Their general direction is similar to that of the 
great Rossie vein. At a place which has been named Mineral 
Point, near the head of Big Island, is a vein of this kind, w^hich is 
apparently of considerable extent, and it contains throughout its 
whole course lead ore, in masses of various sizes. 
