of New-York and New-Jersey, §c. 191 
hornblende. The ledges at Patterson rest on a porous rock 
that lies in a horizontal position resembling the toad stone 
of Derbyshire. Carbonate of lime and other minerals sub- 
ject to decay are imbedded in the rock ; numerous cavi- 
ties, left by their decomposition, give a volcanic aspect to the 
strata. A friable amygdaloid with an argillaceous basis 
was observed in several places, embracing numerous no- 
dules of carbonate of lime of a spheroidal, oval or almond 
shape, from the size of a pea to that of a walnut ; they are 
easily disengaged from the base, and exhibit a smooth dark 
green surface ascertained by Dr. Torrey to be chlorite.— 
The layers beneath the amygdaloid are red and gray con- 
glomerate connected with red sandstone, too porous for use, 
as it absorbs much moisture and is broken by the expan- 
sive power of frost. Good freestone, in nearly horizontal 
position, is the basis layer and forms the bed of the Passa- 
ic. In many places the greenstone occupying the summit 
appears but a few feet in thickness. The greenstone of 
Patterson does not present columns assimilating to basalti- 
form regularity. On the bank of the Passaic, adjacent to 
the first manufactories, I observed a well defined hexaedral 
column of fine grained greenstone, a loose mass, about five 
feet in length by two in diameter ; by the aid of a magnifier 
its greenstone compositionis apparent. Before the autumn of 
1818,prehnite, calcareous spar, and carbonate of copper were 
the only minerals observed imbedded in the greenstone ran- 
ges adjacent to Patterson—at that period I met with, near 
the falls, superior specimens of zeolite, stilbite, analcime, 
and datholite, together with fine masses of prehnite; ame- 
thyst has been since discovered by Judge Kinsey, and Mr. 
J.1. Foote, residents of Patterson—to these gentlemen I am 
indebted for many useful facts. Prehnite I obtained in 
. translucent masses of considerable size, some specimens three 
inches in thickness ; the fibres often radiate from a com- 
mon centre, a mammelated surface is frequently observed, 
considerable lustre is reflected from narrow polished planes; 
the colour-in general a delicate light apple green, but in 
some specimens it is darker than the emerald.—lIt is found 
imbedded in greenstone at the falls. 
The zeolite of Patterson is white, aggregated in fascicu- 
lar groups of delicate diverging fibres, and presenting de- 
tached acicular four-sided prisms of various dimensions, some- 
