843 Hints for the Formation of 8j*c„ 
are thickest in the horizontal part, and give coal of a bet 
ter quality.* 
36. Whether there are several strata, one above the 
other, with banks or other fossils interposed. The qua- 
lity and relation of these strata. 
37. The nature and thickness of the strata of the earth 
or stones under which the coal mine is found ; the im- 
pressions and other vestiges of organised bodies found 
in these strata. 
37 . A. How can those who ascribe the origin of coal 
to forests buried in the earth, explain the very thin strata 
of that fossil contained between banks of calcareous 
stones, and which are repeated at different heights in the 
same mountain ? Hoes not this observation shew that 
there are coal which have originated also from fuci, algas, 
and other marine plants ? 
37. B. Ought we to suppose that all coals have been 
in a state of solution ? What is the agent which dis- 
solved them, and which may be called the mineraliser ? 
38. Though mines of rock salt are commonly found 
in strata, yet M. Fichtel affirms, that there are found in 
Transylvania enormous masses of pure salt, compact, 
and without any appearance of foreign bodies. These he 
considers as of very ancient formation, and distinguishes 
them from those which are in strata between beds of ar- 
gil and free-stone mixed with shells. These important 
facts deserve to be thoroughly examined. 
39. To ascertain the truth of an assertion made by the 
same geologist, that these masses of salt are surrounded 
by ancient volcanoes ; and to determine whether we 
ought to believe with him, that this salt has been crystal- 
lised by the heat of those volcanoes which evaporated 
the water that held them in solution, 
* 35. A. To ascertain whether there exists fossil coal in veins,, as is said to be 
the case at Wehrau in Upper Lusatia° Til. 
