~ 
126 Analysis, §-c. of Cordier’s Essay upon the 
facts known at present, or likely to beomade so. There is 
no proof that the crust .of the earth admits of no vacuities 
between itself and the fused mass. There is no proof of its 
being every where in contact with the fused mass. The 
phenomena of earthquakes and volcanos indicate continu- 
ous cavities of prodigious extent. The earthquake of Lis- 
on, 1755, which shook all Europe and part of Africa, 
took a fortnight to travel across the Atlantic, and four hours 
between Philadelphia and Boston, as appears by the letter 
of Cadwallader Colden, in Phil. Trans. for 1756. There is 
no accounting for this, but by means of continuous cavities 
between the consolidated internal crust, and the fluid mass 
beneath it. The, rumbling noise under ground, attending 
earthquakes, indicates hollow places. _ There is no sufficient- 
_ ly probable evidence, beyond Cordier’s peculiar notion, that 
the slight ‘contraction of the consolidating crust can act 
steam, and the explosion of the gases of decomposed wa- 
“21. The greater part of the substances which mineral and 
thermal waters contain, being analogous to the exhalations from 
craters during and after their eruptions, or from lava-currents 
during crystallization, or from solfaterras, it is reasonable to 
conclude that they proceed from a common source. The emis- 
sions from these waters, lessen continually the interior charge of 
gaseous matter. This loss, continually repaired by new subter- 
ranean products, takes place in consequence of a prodigious ex- 
Pansive force, and by means of very narrow fissures. The wa- 
pers is supplied from above, as springs usually are. The altera- 
stitution of 
nation, we reco 
nearly invariable temperature, and the singular nature of their 
Mn. p: 
certain principles by others. In this system of expla- 
‘ecognize easi 
observations apply to many of the warm springs in 
which Fait eaieees: and sulpt Sued hy- 
