Editobial Committeb : S. Nbwcomb, Mathematics ; R. S. Woodward, Mechanics ; E. C. Pickering ; 



Astronomy; T. C. Mendenhall, Physics; E. H. Thukston, Engineering; Ira Remsen, Chemistry; 



J. Le CONTE, Geology; W. M. Davis, Physiography; Heney F. Osboen, Paleontology; W. K. 



Brooks, C. Hart Merbiam, Zoology; S. H. Souddbr, Entomology; C. E. Bessey, N. L. 



Beitton, Botany; C. S. MiNOT, Embryology, Histology; H. P. Bowditch, Physiology; 



J. S. Billings, Hygiene; J. McKeen Cattkll, Psychology; 



J. W. Powell, Anthropology. 



Friday, Febbitary 23, 1900. 



CONTENTS: 



Are Further Experiments Needed for Determining 

 the Atomic Weight of Oxygen ? : Professor Ed- 

 ward W. MOELEY 281 



57ie Cruise of the Albatross, III : Dr. A. Agassiz.. 288 



The Occurrence of Aptosochromatism in Passerina 

 Cyanea: F. J. Bietwell 292 



Tlie Society for Plant Morphology and Physiology : 

 Professor F. W. Gan'ong 299 



Scientific Books : — 



Carpenter on Insects, their Structure and Life; 

 Professor Vernon L. Kellogg. Ewing's 

 Strength of Materials : M. M. General. Books 

 Received 309 



Scientific Journals and. Articles 311 



Societies and A cademies : — 



Science Cluh of the University of Wisconsin : 

 Professor Wm. H. Hobbs. Zoological Club 

 of the University of Chicago: C. M. CHILD. 

 Biological Society of Washington : T. W. Stan- 

 ton. Section of Anthropology and Psychology of 

 the New York Academy of Sciences: Peofes- 

 soB Charles H. Judd 311 



Current Notes on Physiography : — 



Western Nebraska ; The Mississippi and 31issouri 

 Rivers ; Glacial Lakes and Outlets in 3Iichigan ; 

 Chicago and its Environs: Professor W. M. 

 Davis 314 



Current Notes on 3Ieteorology: — ■ 



Compensation in Weather; Monthly Climate and 



Crop Bulletin: R. DeC. "WARD 315 



Theodore Poesche : O. T. M 316 



Scientific Notes and News 316 



University and Educational News 320 



MSS. intended for publication and books, etc., intended 

 for review should be sent to tlie responsible editor, Profes- 

 sor, J. McKeen Cattell, Garrison-on-Hudson, N. Y. 



ARE FURTHER EXPERIMENTS NEEDED FOR 



DETERMINING THE ATOMIC WEIGHT OF 



OXYGEN?* 



The precision of experiments on the 

 atomic weight of oxygen has been gradually 

 so much increased that, in some cases, the 

 mean error of a single determination is less 

 than 1 part in 10,000. The agreement of 

 diiierent series of experiments is not so 

 good, but if the work of different experi- 

 menters agreed well, the question, how accu- 

 rately do we really know the atomic weight 

 of oxygen, is not one which we can readily 

 answer. Neither the concordance of the 

 experiments of a given series, nor the 

 agreement of the results of series of experi- 

 ments by different observers, can excuse us 

 from search for sources of error. All 

 sciences which have to do with measure- 

 ment afford sufficient instances of the fact 

 that our conclusions are to be received 

 with a certain suspense of judgment. And 

 chemistry well illustrates that he is wise 

 whose assertions regard the possibility of 

 finding at some time evidence to the con- 

 trary. 



The history of experiment on the atomic 

 weight of oxygen affords an interesting 

 example of the fact that neither the con- 

 cordance of individual observations nor 

 the agreement of different experimenters 

 proves that a measurement is right. To- 



* President's address, delivered before the New 

 Haven Meeting of the American Chemical Society. 



