126 Analysis, ^c. of Cot'dier^s Essay iqjon the 



facts known at present, or likely to be made so. There irf 

 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 ma§s. The 

 phenomena of earthquakes and volcanos indicate continu- 

 ous cavities of prodigious extent. The earthquake of Lis- 

 bon, 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 Golden, 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 suflScient- 

 ly probable evidence, beyond Cordier's peculiar notion, that 

 the slight contraction of the consolidating crust can act 

 upon the whole central mass of the globes, especially if it 

 be, as it probably is, elastic. All Cordier's most ingenious 

 hypothesis (for theory it can hardly be denominated) may be 

 true, but it wants farther proof that it is so. The action of 

 steam, and the explosion of the gases of decomposed wa- 

 ter, seem, to us, as yet the most probable cause of volcanic 

 eruptions. 



"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- 

 ter is supplied from above, as springs usually are. The altera- 

 tion of certain parts of the conducting fissures occasions the sub- 

 stitution of certain principles by others. In this system of expla- 

 nation, we recognize easily the permanence of the springs, their 

 nearly invariable temperature, and the singular nature of their 

 principles. Many circumstances lead me to think that these 

 thermal waters were more abundant anciently than now, which 

 may be the consequence of the greater thinness of the crust of 

 the earth formerly, and the greater activity of the process of 

 cooling." 



These observations apply to many of the warm springs in 

 the United States, which yield sulphur, and sulphuretted hy- 



