SCIENCE 



Friday, Septembek 22, 1911 



CONTe:nts 

 The British Association for the Advancement 

 of Science:^ 

 Some Aspects of Modern Petrology: Al- 

 fred Haeker, F.R.S 353 



Letter to the Secretary of Agriculture in re- 

 gard to Clwrges against Officers of the 

 Bureau of Chemistry : President Taft . . . 367 



Professor Josiah Keep : Dr. Wm. H. Ball . . 371 



A New National Mathematical Society: Pro- 

 fessor G. A. Miller 372 



Agricultural Mesearch in Great Britain 373 



The American Mining Congress 373 



Honorary Degrees at the University of St. 



374 



do Notes and A aos 375 



University and Educational News 378 



Discussion and Correspondence: — 



The Grand Canyon of the Colorado: L. P. 

 Noble. Draughts and Colds: T. G. Dab- 

 net. Blanding's Turtle: Dr. C. H. Town- 

 send 378 



Quotations : — 



Medical Practise in Great Britain 381 



Scientific BooTcs: — • 



Publications of the U. S. Naval Observa- 

 tory: Professor A. S. Flint. Bruce 

 on Polar Exploration: General A. W. 

 Greelt 382 



Special Articles: — 



Bandom Segregation versus Coupling in 

 Mendelian Inheritance: Professor T. H. 

 Morgan 334 



MSS. intended for publication and boolts, etc., intended tor 

 review should be sent to tlie Editor of Science, Garrison-on- 

 Hudson, N. Y. 



THE BRITISH ASSOCIATION FOB THE 



ADVANCEMENT OF SCIENCE 

 SOME ASPECTS OF MODEBN PETBOLOGY'- 

 In accordance with the custom which 

 permits the occupant of this chair to open 

 the proceedings with observations on some 

 selected subject, I wish to invite your at- 

 tention to certain points concerning the 

 genetic relations of igneous rocks. The 

 considerations which I shall have to lay- 

 before you will be in some measure ten- 

 tative and incomplete; and indeed, apart 

 from personal shortcomings, this char- 

 acter must necessarily attach to any dis- 

 cussion of the subject which I have chosen. 

 For petrology is at the present time in a 

 state of transition — the transition, namely, 

 from a merely descriptive to an inductive 

 science — and at such a time wide differ- 

 ences of opinion are inevitable. If I should 

 seem to do less than justice to some views 

 which I do not share, I hope this fault will 

 be attributed to the limitations of time and 

 space, not to any intention of abusing the 

 brief authority with which I find myself 

 invested. 



The application of microscopical and 

 special optical methods, initiated some 

 fifty years ago by Dr. Sorby, gave a 

 powerful impetus to the study of the 

 mineral constitution and minute structure 

 of rocks, and has largely determined the 

 course of petrological research since that 

 epoch. For Sorby himself observation was 

 a means to an end. His interest was in the 

 conclusions which he was thus enabled to 

 reach relative to the conditions under 

 which the rocks were formed, and his con- 

 ' Address of the president to the Geological 

 Section. Portsmouth, 1911. 



