134 Hints for the Formation oj 
48. Their connection, if there be any, with lava, fully 
ascertained as such: if it be true, for example, as M. 
Faujas affirms, that currents of lava are seen terminated 
by columns of basaltes. 
43. The nature of the bases on which the basaltes 
rests : whether, as M. Werner says, any is found rest- 
ing on wacke or hornstone, of an earthy and compact 
fracture, which itself reposes on sand or freestone. 
44. Whether at other times basaltes is seen to repose 
on beds of coal ( fwuille ) which present no indications of 
combustion. 
45. In a word, to examine whether the soil which 
bears them, or the sides of the veins in which they are 
contained, present indications of the action of fire, or at 
least of having been exposed to the contact of an incan- 
descent mass ; or, on the contrary, whether there appear 
indications of deposits of a substance which had been in 
a state of aqueous fluidity. 
46. Whether there are in the basaltes vestiges of or- 
ganised marine bodies or others ; and in what state these 
vestiges are found. 
47. Whether there are observed, as M. Faujas says, 
basaltes which seems to have formed a passage for itself 
from top to bottom through masses of granite. 
48. In doubtful cases of this kind it would be neces- 
sary, were it possible to be at the expense, to push a gal- 
lery under a rock of basaltes, to examine whether the co- 
lumns descend below the soil which seems to carry them 5 
and if they are found below the soil, to sink a vertical 
'well to ascertain the truth of the systems which suppose 
them to have been raised from the interior parts of the 
earth through the upper strata. 
