basalt, and trap. 47 
^ em the earth affords no stable resting place, 
re ] paroxysms of volcanic activity, 
^ ® to and fro, and vibrates beneath their 
eet , overthrowing cities, yawning with dreadful 
lasms, converting seas into dry lands, and dry 
Pasl^m')^'' (See Lyell’s Geology, vol. i. 
To the inhabitants of such districts we speak 
a languap which they fully comprehend, when 
we describe the crust of the globe as floating on 
an internal nucleus of molten elements ; they 
have seen these molten elements burst forth in 
liquid streams of lava ; they have felt the earth 
beneath them quivering and rolling, as if upon 
le billows of a subterranean sea; they have 
^en mountains raised and valleys depressed, al- 
T can duly ap- 
ecia e, from sensible experience, the force of 
tr«^i c’^nis in which geologists describe the 
e-irTb r and convulsive agitations of the 
bottn ^ the passage of its strata from the 
orim ° ^ ®^as, in which they received their 
thetfl mountains in which 
they find their present place of rest. 
whirh Streams of earthy matter, 
volrn fusion from active 
shepta^ r spread around their craters in 
mu oh ^ niany kinds of lava ; some of these so 
rocks beds of basalt, and various trap 
lat occur in districts remote from any 
