Sees 
a 
* 
; ap 
2: 
oe a Analysis of Algerite. “ 17 
it will soon be ascertained whether they can be profitably worked - 
ornot. The opinion of a practical miner, on whom I place reli- 
ance, is favorable to some of these mines. It was my intention 
to have examined them myself, this summer, before drawing up 
“omy report, but it has been ordered otherwise. 7 
- « Rich ores of iron have been found in inexhaustible quantities 
_ inthe district of country extending from the Menomonee River 
e 
ad River. I have not had an opportunity of examining the 
-+ localities myself, but I had obtained rich specimens of the ore 
_ from the Menomonee river, in 1844, through the agency of M. 
Barbeau, who obtained them from the Indians, and in 1845, the In- 
» dian chief who furnished those specimens, guided Mr. Pray to the 
on Mountain\near the Menomonee River. During the past sum- 
mer this locality has been also examined by one of my assistants. 
ae 
Arr. X.— Analysis of Algerite; by Ricuarp Crosstey. 
Read before the Bost. Soc. Natural History, by C. T. Jackson, April 17, 1850. 
Tus mineral having been already described in this Journal for 
July, 1849, vol. viii, No. 22, renders it unnecessary to say much 
more on this'head. I have in addition, however, to remark that 
many of the crystals are encrusted with idocrase, and in some 
instances are penetrated, so much so that it required great caution 
© secure such portions as were free from that mineral. The 
‘crystals being cleared of decomposed parts were broken to coarse 
fragments, and the honey-yellow pieces reserved for examination. 
Before the blowpipe, alone, it readily fuses with intumescence 
to a white blebby glass: with soda it gives a dirty-white slag : 
with borax and phosphorus salt it gives a clear bead faintly tinged 
by iron and leaves a siliceous skeleton. Heated in a closed tube 
It gives off water which reacts feebly alkaline, and the powder, at 
first of a light buff color, darkens and assumes a brownish tinge. 
About 1 gramme of the coarse fragments gave a spec. grav. of 
2-78. It isa little harder than cale spar, from 3 to 3-5. 
_ Nearly 2 grammes of the mineral were very finely powdered, 
intimately mixed and divided into two portions. One was ap- 
propriated to the determination of the water and the other for the 
estimation of the carbonic acid. This latter portion was then 
attacked by a mixture of sulphuric and hydrochloric acids. The 
sah mode of analysis was afterwards pursued, and there re- 
Suited :— 
Silica, : : : : 51-27 
Alumina, . ° ‘ ; 23°10 
Peroxyd of iron, . , ; 1-48 
Magnesia, . : : : 5°18 
Carbonate of lime, . ; ; A2L 
Potash, ; : i . 9-97 
