+ 
16 “Rutilated ncaa Cr s Stale ‘atin Vermont. , 
planes of the mineral. In fact, they are cantata ecaginal a 
crystals of mica, twisted or distorted into every imaginable shape.” ” 
heir laminated micaceous structure is shown perfectly by the. — 
microscope, and is represented by the transverse‘liniés in ‘the fig- 
ures. The resemblance of the third figure on the fourth row, to 
some species of Araneides, is not too remote to suggest them in- 
stantly to the mind; and the general resemblance of several of 
the figures to the blood leech and commo n worms is still more ~ 
striking—these being produced by the successively diminishing: 
diameters of the little plates of mica until they terminate nearly — 
ina point. But the origin of these resemblances was evidently’ 
organic matter. They are interesting principally as furnishing a 
new fact in the department of imitative mineralogy, and they a 
propriately suggest the term vermiform mica as most characteristic _ 
of their general appearance. Vermiform should therefore be inclu- 
‘ad among the imitative shapes assumed by mineyals. The strik- 
ing resemblance between several of these figures and the worm- 
like projections thrown out by the separating folia of perrntle 
when exposed to a red heat, will occur to every 
one who has experimented on the mineral. The 
following examples of them were obtained by 
heating a fragment of the pure mineral broken % 
from a specimen lately analyzed in si uk s 
Laboratory. They are of natural s 
The straight lines seen passing tidal several of these figures, 
are intended to show the needles of rutile that actually intersect 
these concretions of mica in the body of the stone. In some of 
them the rutile passes through the circular space left by the fold- 
ing over of the mica, and its crystallization does not seem to be 
interrupted by the mica in any case. A characteristic feature 
of rutile, but never shown in any of the specimens from this 
locality, (i. e., the geniculated forms,) seems to be imitated by 
the mica, and is best shown by the second figure in the lower 
row.* The color of this mica by transmitted light, is a pale 
green, and the mineral seems to agree in external characters with 
the substance from other localities. Considerable quantity of it — 
was found loose in the vein, mixed with broken crystals of rutile.t 
The only appearances at all analogous to those just described, 
* Prof. Hubbard’s za | sige bse eee in so marked a manner, as 
to lead to the impression hey were ru 
+ A portion . ne: car fly se parted was found to lose nearly 15 per cent. of 
water when heated to the melting point of glass, A peculiar empyreumatic odo 
was at the same lows piv - but there was no reaction of fluorine. Ex 
a pets Lo to a white heat‘for twenty minute ; it became grayish 
sed into a state it was slig! magnetic 
Laake sia of “a ms to ally it with pe . a with hydro-mica from the 
fe 
ter see 
Alps— Wasserglimmer of M. Morin ;—while its crystalline form, an oblique rh 
gs apo ose ded figure by the ‘ecallan oF its acute lateral 
