Description of this granite, § 288. Pierre graphique of M. Patrin not perfectly the same with that of Portsoy, § 289. Quartz crystallized in the pierre graphique, § 290. Instances of quartz crystallized in other granites. In that of St Agnes in Cornwall, § 291. Whether this crystallization is only found in secondary granites, § 292.
3. Stratification of Granite.
Question stated concerning the stratification of granite, § 293. Remarkable examples of stratified granite at Chorley Forest, Leicestershire, and at Fassnet Water in Berwickshire, § 295. Stratification of Mont Blanc, and the Aiguilles of Chamouni maintained by Saussure, § 296, 297. Seems nevertheless doubtful, § 298. In the granite mountains of Arran doubtful; § 300. Explanation of the stratification of granite in this theory, § 301. If granitic veins were found proceeding from real granitic strata, they could not be explained on the principles here laid down, § 302. No such veins have been discovered, § 303. Answer to an objection made to the igneous origin of granitic mountains, § 304, 305. Of the proportion of the earth's surface occupied by granite rocks, § 306. Not exceeding a ninetieth part, § 307, 311. Extent of granite in Scotland erroneously estimated by Dr Hutton, § 312. Amounts perhaps to a twenty-fourth of the whole surface, § 313. Observations on Mr Kirwan's opinion, § 314.
Note xvi.—Rivers and Lakes.
The rivers have hollowed out the valleys, § 315. Illustration from the course of the Danube, § 316. Courses of many rivers retain marks of having consisted of a series of lakes, § 317, 318. Filling up and draining of lakes, § 320. Instances from the lakes in Cumberland, § 321. Lake of Geneva, § 322. Lakes in North America, ib. Cataracts, § 323. Difficulties in explaining the generation and continuance of lakes exemplified in that of Geneva, § 324. Attempt to resolve these difficulties, § 325, 326, 327, 328. All lakes not equally subject to them, § 329. Wasting of the land by the rivers, proved from the mouths of rivers on bold coasts, § 330. Examples from Cornwall, § 331.
Note xvii.—Remains of Decomposed Rocks.