42 Assay and Analysis of an Iron Ore. 
Arr. IV.— Assay and Analysis of an Tron Ore, (fer titanné,) from 
the environs of Baltimore,* received through Mr. Warden; by 
T. G. Cremson.+ 
From the specimens received, this mineral appears to be associa- 
ted with a schiste granitoide. Tt is in amorphous masses, possessing a 
parallel division. The exterior surface is of a reddish brown, like the 
peroxide of iron. The interior is of a bright gray, having the tex- 
ture of iron, occasionally presenting indices of crystallization. It 
feebly attracts small particles of iron, and possesses polarity in a 
slight degree. Specific gravity =4.9. 
The following assay was made upon a specimen that appeared to 
be void of gangue. The powder was black, with a tinge of red, 
which indicates the presence of the peroxide of iron. 
Calcined in close vessels, it does not sensibly diminish in weight. 
Twenty grains of this mineral were mixed with ten grains of kaolin, 
(silicate of alumine,) and seven grains of carbonate of lime. The 
mixture was submitted, in a crucible, to the strongest heat of a wind 
furnace. The result of the assay was a culot and scorie, weigh- 
ing in sum, 29.62. The scorie were covered with a thin metallic 
layer, of a copper red, which characterises the presence of the 
oxide of titanium. The interior of the scorie was nitrous, black 
and opake. The iron was white, possessing good properties. It 
weighed, 12. 
Weight of the culot and scoriz, - - - 29.62 
Ten grains of kaolin, calcined, equals, - 10. 
Seven grains of carbonate of lime, - 3.94 
Twenty grains of mineral, - - - 2Q..'.2833.94 
Oxygen, - - - 4,32 
13.94 equals the quantity of kaolin and a ce Now the scoriz 
weigh 17.62. Consequently the kaolin and lime have augmented im 
weight equal to 3.68. 
* Land of Mr. Patterson 
t Extract of a letter Jeois Mr. 7... — to the Editor, dated Paris, 
May 27 
L embrace this opportunity of sending et an er of a process verbal, made 
by myself, at the School of Mines, May Ist, 1829, Considering it of sufficient in- 
terest, will you have the goodness to give ita place in the next number of your ex- 
cellent Journal of Science and Arts. 
