MINERALOGY. 



391 



of SpaJlantani, Portia, Faujas, Breislac, and Cordier. 

 But he did not confine his attention solely to the study 

 of volcanic districts, for he has left several interesting 

 Memoirs on mineral formations. In France, the stu- 

 dy of petrifactions, or fossil organic remains, his mate- 

 rially contributed to the advancement of geognosy. 

 The previous views of Werner, on this subject, the dis- 

 enaries. and observations of Hunter, Blumenbach, 

 Sehlnttheim, and other", paved the way for the more 

 extended and brilliant investigations of Cuvier. 



Whilst geognosy was advancing in other countries, h 

 was until lately but little attended to in Great Britain. 

 The publication of the theory of Bui-net, in 1 6"8 1 , and the 

 ajaecsilations of Robinson in H>99, amused, without com- 

 municating any real information. Woodward's Essay 

 on the Natural History of the Earth, published in 1702, 

 was the first which contained any facts of importance, 

 and the lectures and discourses on earthquakes, by 

 Robert Hooke, in 1705, the physico-theological dis- 

 courses of Ray in 1713, and the new theory of the 

 earth of Whiston, in 1722, were principally of a specu- 

 lative nature. The inquiry into the original state and 

 formation of the earth, by John Whitehurst, published 



good observations on the structure of some districts in 

 England. James Douglass, in 1785, published a dis- 

 jsjlitiis.1 on the antiquity of the earth, in which certain 

 masjl arsjantc remains are particularly considered. 

 About thi* time, Dr. Hutton of Edinburgh, published, 

 in the PkilotojJocal Transaction of the Royal Society of 

 Edinburgh, a striking essay on the theory of the earth. 

 But this work, like all those of a merely speculative 

 , did not afford any beneskial result* to geog. 

 indeed it rexoinrj nearly unnoticed, except m 

 (Controversial tracts by Mr. Kirwan, until it was re- 

 uced to the public by Professor Playfair, in his in- 

 teresting work, entitled " ///sufrelisw* of ike Hxtlornitu 

 Theoiy," publUhed in 1806. In 1801, Professor Ja- 

 meson published, in two volume* quarto, the result* of 

 his observations on the geognosy of the Hebrides, Ork- 

 ney, and Shetland Islands, in a work entitled Mine. 

 raiogy of Ike Scotiufi Itlei. This was the- first exten- 

 sive topographical geognostical work that had appeared 

 in Britain. In 1808, the same naturalist published his 

 Eiemattt of Gtogtoty, in which the structure and ma- 

 terial* of the earth are seicntil drivd. Abml 

 this time the Wernerian Society of Edinburgh, and 

 Society of Lxmdort, were established ; two 

 i which have eminently contributed to the 

 advancement of geognosy. Other geological societies 

 have since been established in different parts of Great 

 Britain ; and the science is now extensively and active, 

 ly cultivated in every civilized country in Europe. 



CHAP. If. 



Detcriftioii of Ire Surface of the arM. 



Gtntr.1 When we take a very general view of the earth, it 



dcnp. appear* as a globular solid mass, whose surface ii di- 



i" vcrt ' Ded by numerous eminences, of various magni- 



* r tudes sod fu 



gat ion. Of these the earthy form the greater portion Goo;nsy. 

 of the earth, while the saline, inflammable, and metal- '"V* 

 lie minerals occur in very various and remarkable re- 

 lations, in the greater and more prevalent masses, yet 

 always in such a proportion, that when viewed on the 

 great scale, they do not contribute to the formation of 

 the figure of the earth or its surface. 



S. When we examine the surface of the globe more 

 particularly, a certain locality of its inequalities is to be 

 observed. Thus the most considerable inequalities, 

 those, namely, which present the most frequent and 

 the deepest sections and fissures, are always found in 

 the more elevated regions ; while in the lower places 

 we observe very few, and by no means such special 

 elevations and depression*. We further observe, that 

 the masses of which the higher and lower parts of the 

 earth are composed, are by no means of the same na- 

 ture. The elevated, rugged, and very uneven places, 

 are mostly composed of rocky masses, which present 

 to the eye rough, bare, and fissured cliffs, mural preci- 

 pices, and even entire rocky valleys. On the other 

 hand, in the lower part* of the earth, we find in gene- 

 ral eaitliy masses, a* day, loam, sand, and rolled 

 tonea ; but neither cliffs nor rocky valleys, and only 

 single blocks of the materials of the more elevated 



2. KM 



i teaches us, that the great fossil 



Experience , n p 



of which die Milid Ixxly ot the earth is composed, 

 when viewed on the great scale, have a tabular farm, 

 and arr consequently more extended in length and 

 breadth than in thickness. 



We also find, that these masse* or rocks are com- 

 posed of different minerals, in various state* of aggrc. 



4. There i* still another general and very interesting 

 observation to be made, namely, that the remains of 

 organic being* more or lea* changed, (what are deno- 

 MlMed pttrifmcttoHt,} are found embedded in these 

 rock*. These remarkable bodies are generally found 

 in the middle and lower heights of the earth, 'in the 

 middle height* they are still very rare; but they in- 

 crease in variety and number, as we approach tin- 

 lower places, and are at length accumulated in immense 

 OMaMkies in the lowest pert*. We also observe, that 

 the organic remains found in the middle heights a e 

 totally dunged into stone ; but the lower the situa- 

 tion, the more these bodies appear unaltered, or ap- 

 proach to their original state. It is also observed, 

 that the higher places afford different genera and spe- 

 cie* of petrifactions from those found in the lower; 

 and although we are able to shew the original* of some 

 of those petrifactions which are found in lower places, 

 as proof* of their origin, those found in the in. 

 heights belong to species that are unknown to u. 

 lastly, we may remark, that in all the situations al- 

 ready mentioned, that is, from the middle to the low- 

 est heights, but particularly in the latter, there are 

 some rock* in which few or no traces of such organic re- 

 mains have ever been found ; although, from the local 

 situation of the rock*, we might a* readily expect to 

 find petrifactions in them, as in other rocks of the same 

 relative height. 



5. When we examine the surface of the earth more Different 

 particularly, we find that the special inequalities are in- specie* of 

 eluded in others more general ; that these general iiie- Im-quahiu 

 qualities are again contained in others still more gene- on th * 



ral ; and that at length the whole are included in the " r h ' ur - 

 most general. These inequalities may be divided into " 

 five classes or degrees. The first contains the most 

 general inequalities ; these are the iolto.n of the tea, 

 and the dry lend. The second comprehends what may 

 be termed lorn country and hifh country. The third, 

 which is more special, comprc -hend- nmunlain ftrowpt. 

 The fourth, which is still more particular, compre- 

 hends iniiHiitiiiH c -'.(i/;M and i'nliri/i. The filth and last, 

 which is the most special, comprehends tingle mimn- 

 laint, and the ravine* or valleys between them. We 

 have thus a most beautiful series from the single moun- 



