352 
APPENDIX. 
This ore was infusible without addition, but on adding to it 
0,10 of pure silex, and 0,075 of chalk, it melted readily ; and 
yielded a grey scoria, slightly transparent, and a button with a few 
grains, weighing together 0,69 : the button was very grey and 
semi-ductile ; it flattened under the hammer before it broke. 
The second variety of ore had nearly the same appearance as 
the first, but it was more homogeneous, and its colour a lighter red, 
and less shaded with yellow ; it was remarkable for its lightness, 
and this led to the analysis of it ; its specific gravity was found 
to be only 2,25. It loses by calcination 0,247 of its weight, and 
this loss is owing to pure water. This was ascertained by distilling 
part in a glass retort with a red heat ; its colour is not perceptibly 
changed by this operation, it only becomes of a deeper red, which 
proves that the oxide of iron which it contains is not, at least not 
the whole of it, in a state of hydrate. When treated with boil- 
ing nitric acid, the acid dissolves much alumine, and a little oxide 
of iron. Muriatic acid produces a contrary effect, and dissolves all 
the oxide of iron, and part of the alumine. If the action of this 
last acid be prolonged, there remains a white residuum, which 
weighs from 0,15 to 0,16 ; but if it be kept in ebullition on the ore 
for some hours, it dissolves almost all the alumine, and the insoluble 
residue calcined weighs only from 0,05 to 0,06. This residue is 
composed of silex and alumine, which cannot be completely sepa- 
rated, except by potash, and which appear to be united in an argil- 
laceous state. The complete analysis gave : 
