232 



RECORD OF SCIENCE FOR 1887 AND 1888. 



Examinatioi) of this system of classification shows that it has 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 form 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 i)redominantly 

 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 ISorth American Ge- 

 ology."* It is as follows: 



CLASSIFICATION OF OKOI.OOY. 



f of masses 



? < of parti- 

 ^ cles, the 



i< 



t< 



incl 



lule < 



pro- 

 cesses of I 



11 nrf» » 



f uiotiou ■{ 



change, 

 depend- 

 inji on 



agency 

 l)eing 



Hiolecnlai'.. .. 

 , transmutation of motion 



products f i"cks ( tunr 

 of < variously \ arrt 



change 



mposed . 

 auged . 



forms 



O 



f geographically .... 



^are distributed.. . <| 



solid .(1) Diastrophic geology. 

 Unid .{2) Volcanic geology, 

 ice . ..(3) Glacic geology, 

 water (4) Hydric geology. 

 < wind. (r>) Eolic geology, 

 life ..(6) Biotic geology, 

 man .(7) Authropic geology. 



(8) Chemic geology. 



(9) Circulation geology. 



(10) Lithology. 



(11) Petromorphic geology. 



(12) Geomorphic geology. 



(13) Alabama. 



(14) Alaska. 



Etc. 



1 chronologically 



Geologic literature treats also of two arts 



.(61) Historic. 

 .(62) Quaternary. 

 Etc. 



.(74) Geologic techuology. 

 .(75) Economic geology. 



While the subject-matter is thus divided into processes and products, 

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

 the category of processes is given a leading i)lace 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 importaiu;e of agencies 

 and conditions in classification on the one hand and objective phenom- 



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

 of four pages. 



