G E O 



[ 104 ] 



G E O 



roundish piece of mineral matter, some- 

 times only an incrustation, generally 

 more or less hollow, usually lined with 

 crystals, or in some cases loose earthy 

 matter. The geodes found in the green- 

 sand near Sidmouth, says Mr. Bakewell, 

 in his valuable Introduction to Botany, 

 are composed of opaque chert on the 

 outside, and contain within, mammil- 

 lated concretions of beautiful chalcedony, 

 and occasionally perfect minute rock- 

 crystals. 



GEO'GNOSY. (from ytj and yi/w<nc, Gr.) 

 That branch of natural history which 

 treats of the structure of the earth. 

 Werner and his disciples, as well as some 

 of the French geologists, have substituted 

 geognosy for geology, the former derived 

 from y>) and yvaxri^, the latter from yrj 

 and Xoyoc: Mr. Bakewell has justly ob- 

 served, for this change no sufficient reason 

 can be assigned, and it is contrary to 

 established analogies of language. No- 

 thing can be more unmeaning than the 

 apologies that have been offered for sub- 

 stituting yvuxriQ, knowledge, for Xoyoc, 

 reason. By the same rule we ought to 

 change meteorology, physiology, &c. into 

 meteorognosy, physiognosy, &c. Sake- 

 well, Introduction to Geology. 



GEOLO'GICAL. Pertaining to the science 

 of geology. 



GEO'LOGIST. One versed in that branch of 

 natural history which treats of the struc- 

 ture of the earth. 



GEO'LOGY. (from -yij and \oyoc, Gr.) Geo- 

 logy may be defined to be that branch of 

 natural history which investigates the 

 successive changes that have taken place 

 in the organic and inorganic kingdoms of 

 nature. It is a science founded in exact 

 observation and careful induction ; it 

 may be termed the physical history of 

 our globe ; it investigates the structure 

 of the planet on which we live, and ex- 

 plains the character and causes of the 

 various changes in the organic and inor- 

 ganic kingdoms of nature. It has been 

 emphatically termed the sister science of 

 astronomy, ranking, undoubtedly, in the 

 scale of sciences, next to astronomy, from 

 the sublimity of the objects of which it 

 treats. 



Geology is as intimately related to al- 

 most all the physical sciences, as is his- 

 tory to the moral. As the historian 

 should, if possible, be at once profound- 

 edly acquainted with ethics, politics, juris- 

 prudence, the military art, theology ; in 

 short, with all those branches of know- 

 ledge, whereby any insight into human 

 affairs, or into the moral and intellectual 

 nature of man can be obtained ; so is it 

 desirable that the geologist should be 

 well versed in chemistry, mineralogy, 



zoology, botany, comparative anatomy ; 

 in short, in every branch of science 

 relating to organic and inorganic nature. 

 " It was long," says Prof. Lyell, " ere 

 the distinct nature and legitimate objects 

 of geology were fully recognised, and it 

 was at first confounded with many other 

 branches of inquiry, just as the limits of 

 history, poetry and mythology, were ill 

 defined in the infancy of civilization." 



Werner appears to ha\e regarded geo- 

 logy as little other than a subordinate 

 department of mineralogy, and Desmarest 

 included it under the head of physical 

 geography. Dr. Button, in his treatise, 

 published in 1795, first endeavoured to 

 draw a positive line of demarcation be- 

 tween geology and cosmogony, declaring 

 that geology was in no ways concerned 

 with questions as to the origin of things ; 

 and, in fact, geology differs as widely 

 from cosmogony, as hypothesis concern- 

 ing the mode of man's first creation differs 

 from history. Philosophers for some 

 ages past neglected the examination of 

 the earth, contenting themselves with 

 vain speculations respecting its forma- 

 tion ; and to Strabo, who flourished under 

 Augustus, and died under Tiberius, about 

 the year 25, and to the old philosophers, 

 who studied the local phenomena of their 

 countries, would the title of geologists 

 with more propriety be given than to 

 Burnet and Buffon, whose systems of 

 cosmogony have more the air of a system 

 of romance, than of a serious generaliza- 

 tion of facts. In tracing the history of 

 geology from the close of the seventeenth 

 to the end of the eighteenth century, we 

 find the science retarded by the wild and 

 visionary speculations of a host of writers ; 

 to enter on these would, however, far 

 exceed the limits of a work of this kind, 

 and those desirous of so doing, I would 

 refer to Mr. Ly ell's admirable work, 

 Principles of Geology. 



Hutton, following the example of New- 

 ton in astronomy, endeavoured to give 

 fixed principles to geology ; but, at that 

 time, too little progress had been made 

 in the science, to enable him to realize so 

 noble a project. A brighter period has 

 now dawned, and the following out the 

 only true method, namely, that of keep- 

 ing within the boundary of inductive 

 philosophy, has led to the most important 

 results. 



One of the greatest difficulties with 

 which geology has had to contend, is the 

 false notion entertained by many well- 

 meaning but weak persons, that geology 

 was opposed to Scripture revelation, and 

 that geological researches might prove 

 injurious to religion. Unfortunately, 

 prejudice and ignorance have too fre- 



