230 Dr Hibbert mi the Distribution 
strata. A thin stratum of limestone is observed near Sonsoness 
to penetrate a small mass of granite, its course through the rock 
being in a very remarkably degree distorted. There is, at the 
same time, an intermixture of the substances of which both 
rocks are composed. 
It is owing to the general presence of those small insulated 
masses to which the character of nuclei has been assigned, that 
it would be very difficult to speak with much degree of accuracy, 
respecting the general direction or dip of the strata^among which 
such interrupting masses occur. The most prevalent direction 
seemed to be fromN. tcN. 45® E. The actual course of the strata, 
however, considered en masse^ is certainly from the bluish-grey 
quartz of Walls and Aithsting, to the granite of Vementry and 
Meikle Rheu. The Junction of the quartz with the strata of 
gneiss, is perceptible throughout nearly the whole line of boun- 
dary described ; but the junction of the gneiss with the granitic 
mass to the north, is only manifested in the Island of Vemen- 
try ; elsewhere, it is concealed by the approach of the sea. In 
Vementry may be observed a few very remarkable invasions of 
the gneiss, by processes from the mass of granite. In the pro- 
montory of the Neing, also, there is probably a similar invasion 
from the granite of Meikle Rheu ; for to such a connection, 
though concealed by the sea, may perhaps be referred the pene- 
tration of the strata of gneiss, by a veinous mass measuring 45 
feet in width. 
&hly, The Red Quartz-Rock of the Hill of Walls , — The 
bluish-grey quartz before described, is connected in its northern 
boundary line with another but smaller mass of quartz, the 
colour of which is, according to Werner’s nomenclature, cochi- 
neal red. The red quartz also contains felspar in its composi- 
tion ; it is at the same time unstratified. The rock may be geo- 
graphically described, as forming the hill of Walls, having an 
elevation of nearly 1200 feet above the level of the sea. The 
form of this mass of red quartz, as induced by a horizontal sec- 
tion, is very nearly similar to that of the bluish-grey quartz. 
There is only this difference, that, in the red quartz, the an- 
gular apex from which the divergency of its bounding lines 
is continued, is bent outwards so as to be separated from 
the bluish-grey quartz to which the rock is elsewhere join- 
