390 Miscellanies. 
clothe the tops of the rocks, and the borders of the stream below the 
falls,—imparting tothe place in a high degree, the effect of seclusion. 
When the river is swollen by the spring freshets, the noise of the 
waterfall is heard to the distance of several miles. 
The trap wherever it comes into view, presents numerous empty 
cavities, some of which are an inch or two in diameter. By break- 
ing into the rock, a little way from its surface, these cavities are 
found, still occupied with the Datholite and other imbedded minerals. 
But specimens are procured more conveniently from among the larg- 
est fragments of the trap which surround the base of the hills direct- 
ly below the falls. ‘The Datholite forms seams and amygdaloidal mas- 
ses, varying from one inch to two inches inlength. ‘These seams and 
masses are either wholly composed of the mineral, or have within, cav- 
ities of larger or smaller dimensions. In the former case, the mass 
is fibrous or granular,—the two varieties never occurring together, 
but the whole mass is either made up of delicate, radiating fibres or 
composed of fine granular individuals. Where a cavity is found 
within the mass, its walls are lined with the most brilliant crystals 
which surmount, or are situated upon, the internal extremities of the 
fibres. These crystals are completely transparent and colorless, or 
are translucent with a faint tinge of yellow or green. 
This locality is rendered the more interesting, inasmuch as it pre- 
sents us with the connexion among what was formerly considered as 
forming three distinct species: viz. Humboldite, Datholite and Bo- 
tryolite. For its crystals give the principal measurements of the 
two first mentioned cnboeees ; and the fibrous, semi-botryoidal 
properties which it manifests in other specimens, show its relation to 
Botryolite. : 
It deserves to be rian remarked in description of the fibrous vari- 
ety afforded by this locality, that the fibres where they commence ra- 
diating from the exterior of the mass and where they are in juxta- 
position with the trap, are sometimes of a pale, flesh-red color: at oth- 
ers, they are milk white; and so close is the aggregation of the individ- 
uals, that the naked eye can with difficulty detect the fibrous texture. 
The hollow masses of Datholite contain occasionally, a transparent 
bluish Selenite ; and also a bluish Calcareous Spar, which is some- 
times in regular crystals of the cuboid form and constitutes appar- 
ently, the Prunnerite of Esmark. Small geodes of Chlorite and 
of a delicately green Prehnite exist also in the same rock, but the 
Datholite is never immediately associated with any other substamee 
than the one above mentioned. 
