1829.] 
Analysis of Iron Ores. 
297 
iVo. 5. Paolta Kanowa , Sp. Gr. 3,587. 
Phenomena with the Blowpipe. Scintillates, becomes magnetic, and acquires the 
metallic lustre ; with borax on charcoal, fuses, with slight ebullition, into a very- 
opaque green glass. 
Constituent parts. 
Water, 7,00 
Silex, 7,90 
Alumine, 0,60 
Lime, 0,00 
Phosphate of Iron, Trace 
Oxyde of Manganese, 10,25 
Peroxyde of Iron, 74,00 
99,75 
A r o. 6, no Label with this Specimen, Sp. Gr. 2,857. 
Phenomena with the Blowpipe. Becomes magnetic, and externally, of a metallic 
lustre ; with borax on charcoal, a dark enamel. 
The pulverised ore, like No. 1, is of a pale yellow brown, changing to a deep 
chocolate red in calcination. 
Constituent parts. 
Water and Carbonic Acid, 
9,50 
Silex, 
27,50 
Alumine, 
1,50 
Oxyde of Manganese, 
9,00 
Deut-Oxyde of Iron, 
51,00 
98,50 
Note. — Like No. 1, this specimen acquires weight (about 8| per Cent.) by 
digestion in nitric acid : it is certainly too poor an ore to be smelted, unless under 
very favourable circumstances ; but trials might be made of its effect on the qualities 
of iron produced from mixtures of it with other ores, there seem to be grounds 
for supposing, that, silica sometimes combines with iron in the metallic state. 
Nn . 7, Deser Gerh, Sp. Gr. 3,645. 
Phenomena with the Blowpipe. Becomes magnetic, and assumes the metallic tar- 
nish; with borax on charcoal, a dark coloured enamel, studded with bright gold 
spots, resembling avanturine ; the fragments translucent, and of a bright golden green. 
Constituent parts . 
Water, 6,00 
Silex, 3,75 
Lime, - 0,50 
Alumine, 6,50 
Phosphate of Iron, 0,90 
Oxyde of Manganese, 1,50 
Peroxyde of Iron, 86,00 
99,15 
K ote —The very beautiful appearance produced by the blowpipe, may probably 
be owing to the conversion of phosphate of ironinto phosphuret of iron, by the com- 
bustion of tbe charcoal support. . ,. . . 
The process used in the foregoing analyses differs from those indicated by 
books ; I have therefore subjoined a memorandum of it for the satisfaction of the 
scientific chemist. _ . , , , , 
1 Weigh the pulverised ore at the temperature of the atmosphere, and calcine, 
at a low red heat: the loss indicates the water; and if there is change of colour 
(from Yellow to deep red brown) probably of carbonic acid. 
2 For 100 grains of tlic ore take i(, ox. muriatic acid, bod it gently over a 
lamp in a covered vessel for twenty minutes, add tour ounces of water, and boil 
again for a few minutes ; this dissolves every thing except the silica, alumina, 
phosphuret of iron (if any exists), sulphate and phosphate of lime : filter and wash 
the residuum perfectly, and calcine it ; its weight is that of the silica and alumina— 
it may he tested for phosphate and sulphate ot lime if necessary. 
