232 Dr. Cooper on Volcanoes 
No difference in appearance can be pointed out between 
the basalts of Saxony and Lavas, as has been before ob- 
serve 
No difference has been shewn in the chemical, or in the 
mechanical characters of basaltic Lava, and basaltic ficetz 
Gordier’s paper on the substances that compose the mass 
of voleanic rocks of all ages, has shewn that augit, horn- 
blende, felspar, and titaniferous iron ore, are the compo- 
nent parts equally of flaetz trap and of Lava-basalt. Journ. 
de Phys. Tom. 63. 
The more the fleetz trap regions are examined, the more 
decided marks of former craters are discovered. Until the 
numerous craters in and about Rome were discovered, this 
volcanic region would have passed for a country cov vered by 
fleetz trap ; just as Auvergne yet is, notwithstanding the 
numerous craters of extinct volcanoes, traced and noticed 
by Soulavie and others. 
[tis impossible to account for the: pores in basalt, but from 
the violéns extrication: of ai,’ or steam while in a soft or 
fluid. ve do for the pores in Lava: or for the carbo- 
nat of pets prehnites, zeolytes, agates, &c. that are formed 
in those pores, as we do for similar substances gradually in- 
filtrated and crystallized in the pores of Lava 
The experiments of Sir James Hall, Mr. Gregory Watt, 
and Dr. Hutton, on Whin-stone, and Rowley Ray, confirm 
the volcanic origin of these stones as ae now appem: 
Hence then it appears, stated briefly, tha 
Lavas The FI. trap foanations $5 
ontain as their greatest proportion,| Contains as ro greatest propor- 
rocks not to be So Aig ay Mes in any|tion, rocks not to be distinguished 
way ; trap bas from basalti 
toand are acconipa-| So are hate trap rr eealic 
They are accompanied by granite,| Such is the case also of floc 1 trap 
gneiss, mica mica slate, sienite and other basalt. See particularly Dr. MiCul. 
on the Granite of Aber- 
res +e. 9. 
various quantities, deen-shire, a his remarks on the 
isienite o Scotch Isles. So, when 
Von Buch and Haussman were at 
Christiana in Norway, the exclama- 
tion was, sui’je en Auvergne. 
