232 



RECORD OF SCIENCP: FOR 1887 AND 1888. 



Examination of this system of classification sllo^YS that it lias a triple 

 basis — the agencies and conditions of geology form one of the elements, 

 the generalized objective phenomena of geology form another, and the 

 applications of geologic science lorm a third ; and the classes are neither 

 CO ordinate nor definitely seriate, while the minor divisions of each must 

 be made on unlike bases. The classification is intermediate between 

 the purely objective systems which went before and the predominantly 

 genetic systems which were evolved from it. 



In the autumn of 1884 a more elaborate scheme of classification of 

 geology was developed by Gilbert, and discussed at the meeting of the 

 British Association for the Advancement of Science, at Montreal, under 

 the title of a "Plan for a Subject-Bibliography of North American Ge- 

 ology."* It is as follows: 



CLASSIFICATION OV OEOLOOY. 



1 51 



( solid .{I 



f of masses \ a ■ , ,. 

 ( nuid .(2 



of ])arti 



S^ 



iiicliule < 



pro- 

 cesses 

 change, 

 depend 

 inii' on 



4 



f motion i 



solid .(1) Diastrophic geology. 



(2) Volcanic geology, 

 ice - ..(3) Glacic geology. 



water (4) Hydric geology. 



cles, the • i /r\ t7 i- i 



' < wind- (5) liiOlic jieolojjy. 



agency ' ■^ a aj 



l)eiu<r life ..(6) Biotic geology. 



man .(7) Aiithropic geology. 



molecular (8) Chemic geology. 



transmutation of motion (9) Circulation geology. 



composed (10) Lithology. 



red (11) Petromorphic geology. 



c compoi 

 c arrauji 



products f rocks 

 of ^ variously 



c lange l^f^j.,,^^ ^2) Geomorphic geology 



O 



.are distributed.. . { 



f geographically 

 I 



[ chronologically 



Geologic literature treats also of two arts 



.(13) Alabama. 

 .(14) Alaska. 

 Etc. 



.(61) Historic. 

 -(62) Quaternary. 

 Etc. 



. .(74) Geologic technology. 

 . .(75) Economic geology. 



While the subject-matter is thus divided into i)rocesses and products, 

 and their distribution in time and space are also elements in this scheme, 

 the category of processes is given a leading place in the classification. 



During 1887 and 1888 some minor contributions were made to the 

 subject by different authors, and the influence of gradual modification 

 in fundamental conceptions as to the relative importance of agencies 

 and conditions in classification on the one hand and objective i^henom- 



* Rep. British Assn., 1884, p. 732. The plan was also set forth in a printed leaflet 

 of four pages. 



