206 _ J.D. Whitney on Pectolite. 
Von Kobell’s analysis of the Monte Baldo pectolite, the silicais 
given at 51:3 per cent, while other analyses of Seotch and 
American varieties give as much, in some instances as 54 and 
55 per cent of that substance. In the like manner, the amount 
of lime, as stated by different analysts, varies from 298 a 
per cent, while there is even less agreement in the water, which — 
Is given at from 0°41 to 3°89 per cent. : 
The difficulty of procuring, in a perfectly pure state, a mine 
ral which only occurs in a finely-fibrous condition is undoubt 
edly one of the principal causes of these discrepancies in the 
analyses; but it is also possible that the unus required 
for the correct determination of the silica in the very soluble 
class of minerals to which pectolite belongs may not, in all cases 
have been appreciated. The great abundance and purity of the 
‘specimens of this mineral which have been obtained from the — 
tunnel of the Erie railroad, recently excavated ape 
Hill, seemed likely to obviate the first difficult mentioned ’ 
above. The results of three analyses indicated that this ma 
terial was really of almost absolute purity, while no pains wee 
spared to effect a complete and accurate separation of the vanows 
a ~ 
The pectolite dissolves more or less completely in ieee 
ss 
° 
Kr 
tf 
far) 
oO 
Qu 
ot 
° 
or 
=) 
<q 
fas) 
P. 
far) 
=] 
2, 
Pail) 
pe) 
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aS) 
ct 
= 
o 
m 
2 
Ss 
er 
°o 
Bp 
< 
4 
= ‘ * on sé ating | a ; 
was stirred with a glass rod or the spatula; eet mi 3 
its amount was 8°” 
contaminated by any traces of the bases, it was ii 
to use the unignited substance for the attack wl 
