498 Mr. He ns low’s Supplementary Observations to 
be seen on the beach, a few yards to the north of the small patch 
of limestone there, from whence it runs inland in a westerly 
direction forming, a ridge eight or ten feet broad. It rests on the 
schist, and thin veins project from it downwards. There is a bed 
of trap resembling the more compact varieties of that at Scarlet, 
but not amygdaloidal, lying to the north of the Peel sandstone. 
It rises from the sea, and penetrates the schist in the form of dykes. 
Hornblende slate is seen behind the Garth, near Kirk Marown, 
but whether in contact with the gneiss there, I was not able to 
determine, owing to an intervening spot of cultivated land. 
SIMPLE MINERALS. 
I have but little to add to Dr. Berger’s list of simple minerals. 
Fibrous Actinolite occurs in a decomposing state near the Dun, 
in two veins, each about six inches broad, traversing the decomposed 
portion of the granite and gneiss. It is accompanied by quartz, which 
it penetrates and frequently colours. It may be taken from the 
vein in fibrous bundles of three or four inches in length, but it 
is in general so much decomposed as to have assumed an earthy 
form. In this state it is mentioned by Dr. Berger, p. 54, under 
the name of Dun earth. On pressing the fibres between the fingers 
they crumble to a harsh powder capable of taking away the polish 
from glass, and consequently very unfit to be used in cleaning plate, 
a purpose to which it has been applied. I found a single specimen 
in which the fibres were flexible. Specific gravity=3,03. 
I met with a worn lump of the arseniate of lead among the 
rubbish of the Laxey mine. 
Veins of chlorite occur in different parts of the island traversing 
the clay-slate, and often colouring the quartz by which they are 
accompanied. 
