a Theory of the Earth » &Q7 
compact calcareous, is not often a breche,* the angular 
fragments of which are for the most part of the same na 
ture as the stratum that serves them as a basis, and unit 
ed by a cement of the same nature ? f 
5. (A). To observe in the chalk mountains the flints 
contained there ; their bulk, their form, &c. ; whether 
they are disposed in beds ; to reflect on their origin : even 
researches on the petro-silex contained in the compact 
calcareous stones ; and, lastly, the same on the hard rog~ 
nous, or touch -stones contained in the slate mountains : 
to ascertain whether these petro-silex and rognons are 
not found in the primitive mountains. 
6. Whether there are found in secondary mountains 
festiges of organized bodies, and at what elevation. 
This observation is important above all in the Austral 
hemisphere. J 
7. Whether there are found, either at their surface, or 
in their interior parts, rolled pebbles or blocks of a na- 
ture different from that of the same mountain, and to 
what height ? || 
8. Whether these mountains seem to have been form- 
ed by the alluvion of violent tides, or by the accunmlat 
ed deposits of stagnant water ? 
9. Whether the secondary mountains do not present 
themselves sometimes in vertical strata, or at least strata 
very much inclined, and w ith sharp naked peaks like 
those of some primitive mountains ? 
10. Whether, in the same secondary mountain, there 
are found strata of different kinds of stones oftener than 
in the primitive ? 
* Breche is a kind of hard marble found in the Pyrenees, 
f Voyage dans les Alpes, vol. i. § 242. A. and 243. 
+ 6. A. Do not organized bodies contribute sometimes to the hardness of 
stones^ especially those that contain iron, by bringing that iron near to the me- 
tallic state ? Hypothesis of Gad in Mem. of the Acad, of Sweden^ 1787. Til 
|| S'ee Dolomieu’s Memoir, Journal de Physique, 1791, vol, ii 
