INTERCONNECTION OF THE SCIENCES. 87 



made tip for by the address of their excellent President, 

 Mr. Grant- Duff, whose appointment to the Governor- 

 ship of Madras, while occasioning so sad a loss to his 

 friends, will unquestionably prove a great advantage to 

 India, and materially conduce to the progress of science 

 in that country. 



Moreover, several other subjects of much importance, 

 which might have been referred to in connection with 

 these latter Sections, I have already dealt with under 

 their own more purely scientific aspect. 



Indeed, one very marked feature in modern discovery 

 is the manner in which distinct branches of science 

 have thrown, and are throwing, light on one another. 

 Thus the study of geographical distribution of living 

 beings, to the knowledge of which our late general 

 secretary, Mr. Sclater, has so greatly contributed, has 

 done much to illustrate ancient geography. The exist- 

 ence of high northern forms in the Pyrenees and Alps 

 indicates the existence of a period of cold when Arctic 

 species occupied the whole of habitable Europe. Wal- 

 lace's line as it has been justly named after that dis- 

 tinguished naturalist points to the very ancient 

 separation between the Malayan and Australian re- 

 gions ; and the study of corals has thrown light upon 

 the nature and significance of atolls and barrier-reefs. 



In studying the antiquity of man, the archaeologist 

 has to invoke the aid of the chemist, the geologist, the 

 physicist, and the mathematician. The recent progress 

 in astronomy is greatly due to physics and chemistry. 

 In geology the composition of rocks is a question of 

 chemistry and physics ; the determination of the boun- 

 daries of the different formations falls within the limits 



