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Mr. Hatchett’s Analysis of the earthy Substance 
centrated muriatic acid, and digested it for two hours in a 
strong sand heat. Boiling water was then added, and the 
whole being poured on a filter, the residuum was edulcorated, 
dried, and made red-hot ; it then weighed 85.50 grains. 
C. The filtrated solution was evaporated to one fourth, and 
pure ammoniac being added, a precipitate was formed, which, 
after a red heat, weighed 10.70 grains. 
D. One ounce of muriatic acid was poured on the 10.70 
grains, in a matrass, which was then heated. The whole of 
the 10.70 grains was dissolved, excepting a small portion of 
siliceous earth, which weighed 0.30 grain. 
E. The muriatic solution was then reduced by evaporation, 
to about one fourth; to which I added a large quantity of dis- 
tilled water, which did not however produce any change. I 
then gradually added a solution of pure crystallized prussiate of 
potash, and heated the liquor till the whole of the iron was pre- 
cipitated; after which, ammoniac precipitated a loose white 
earth, which, edulcorated and made red-hot, weighed 7.20 grains. 
The iron precipitated by the prussiate may therefore be esti- 
mated at 3.20 grains. 
F. The 7.20 grains of the white earth were digested with 
sulphuric acid, and, after the excess of acid had been expelled 
by heat, boiling water was poured on the saline residuum. 
The solution was then gradually evaporated, with the addition 
of a small portion of lixivium of potash, and afforded crystals 
of alum, without a trace of any other substance. 
G. I > now proceeded to examine the 85,50 grains of B. 
These appeared to consist of siliceous earth, or fine particles of 
quartz, mingled with a considerable quantity of the dark grey 
shining particles. 
