333 
a Theory of the Earth , 
37* When these characters are discovered, to exa- 
mine whether, in the neighbourhood of the doubtful 
mountain, there are found scattered stones which exhibit 
the same characters, and which seem to have proceeded 
from that mountain. 
38. To observe whether there are found, in the neigh- 
bourhood of the doubtful mountain, any vestige of the 
remains of heat concealed in the bosom of the earth, as 
of thermal, or even acidulous waters. It is well known 
that these signs are equivocal, but their combination with 
others may throw some weight into the scale. 
38. A. Whether there exist certain proofs of alternate 
deposits of lava or other volcanic productions, and of 
matters accumulated or deposited by the sea. 
39. Among the stones changed by the fire, to discover 
those which may be considered as having been subjected 
to the action of one stratum of coal in deflagration, and 
which the celebrated Werner calls pseudo-volcanic, and 
to distinguish them from those which have been fused in 
a real volcano. 
40. Basaltes : their forms in columns, in beds, round 
masses ; their connections, the relation which the ba- 
saltes of these different forms observe with each other. 
41. The nature of these basaltes : that of their tex- 
toe, of the points which they contain, of the pores and 
empty or full cells that may be observed in them ; of their 
different accidents and decomposition. 
41. A. The phenomena they exhibit in the fire, either 
exposed to, or sheltered from the action of the air. But 
before any arguments are drawn from these experiments, 
it will be necessary to resolve the question, Whether it 
be true that a stone may have been melted by subterra- 
nean fire, and yet none of its characters exhibit those in- 
dications of fusion which the fire of our furnaces would 
have given to the same stone. 
