404 Scientific Intelligence. 
(3.) By the second method, that of prolonged digestion, we have actu- 
ally made with carbonated water, and even with simple water, a par- 
tial analysis of a number of complex minerals. The specimens expo- 
sed to the CO, water for forty-eight hours, and to the simple water for 
one week, have in many instances furnished a sufficient amount of ma- 
terial to the liquid, to admit of a quantitative examination. ‘Thus, from 
hornblende, actinolite, epidote, chlorite, serpentine, felspar, mesotype, 
&c., we have procured a quantity of lime, magnesia, oxyd of tron, 
alumina, silica and alkali, the dissolved ingredients of these minerals 
e 
ate to that of peroxyd during the evaporation, collects in brown floc- 
culi, along with the silica and alumina at the bottom of the capsule. 
Thus, 40 grs. of hornblende} digested for forty-eight hours in CO, wa- 
ter at 60°, with repeated agitation, yielded silica 0-08, oxyd of iron 
0-05, lime 0°13, magnesia 0°095, manganese a, distinct trace. 
(4.) Most of the substances above enumerated, when finely powdered 
in an agate mortar, and moistened ‘with pure water in a platinum cap- 
sule, give decided alkaline reaction with test paper properly prepared, 
mong the materials presenting this effect most strongly, are serpen- 
carbonated water quite a discernable amount of alkali. 
) The comparative readiness with which the magnesian and calca- 
reo-magnesian silicates yield to the decomposing and dissolving action 
of carbonated and even simple water, is we believe a fact no less im- 
portant than it is true. It explains the rapid decomposition of t 
rocks composed mainly of hornblende, epidote, chlorite, &c., without 
calling in the agency of an alkali, and it accounts for the fact that rocks 
magnesia they require, from soils containing these silicates, without our 
having recourse to any mysterious decomposing power of the roots of 
the growing vegetable. 
(6.) Among the points of interest incidentally determined during thes? 
investigations, may ntioned the curi nd instructive fact that 
anthracite coal, bituminous coal, and lignite, treated by the tache pr? 
cess, give unequivocal evidence of alkali, while the ashes of t ” 
terials similarly treated, yield no trace of alkali. It thus becomes ev! 
dent that the absence of alkali in the ash of these combustibles, instead 
