SCIENCE 



A WEEKLY JOURNAL DEVOTED TO THE ADVANCEMENT OF SCIENCE, PUBLISHING THE 



OFFICIAL NOTICES AND PRO^CEEDINGS OF THE AMERICAN ASSOCIATION 



FOR THE ADVANCEMENT OF SCIENCE. 



Friday, September 29, 1905. 



CONTENTS. 



The Progress of Physics in the Nineteenth 

 Century, II. : Professor Carl Barus 385 



Scientific Boohs : — 



Fieherger's Civil Engineering : Professor 

 H. N. Ogden. Duckwo7-th's Morphology 

 and Anthropology : T. D 39/ 



Scientific Journals and Articles 399 



Discussion and Correspondence: — 



The Letter K in Zoological Nomenclature: 

 T. D. A. COCKERELL. ' Eammock,' ' Horn- 

 mock ' or 'Hummock'? : Roland M. Har- 

 per. Indian Bone Comhs: The Rev. W. M. 

 Beauchamp 399 



Special Articles : — 



The Systematic Name of the -Japanese Deer: 

 Dr. Leonhard Stejneger. The Possibility 

 of Absorption by Human Beings of Nitrogen 

 from the Atmosphere: Dr. Axel Emil Gib- 

 son 402 



Quotations: — 



Mr. J. B. Burke's Experiments ; The Chi- 

 cago Death Rate 405 



Current Notes on Meteorology : — 



The Monthly Weather Revieio ; Islands for 

 Purposes of Weather Forecasting ; Meteor- 

 ology and other Sciences ; A New Text-book 

 of Meteorology ; Notes: Professor R. DeC. 

 Ward 407 



Notes on Inorganic Chemistry : — 



Solutions in Liquid Ammonia: J. L. H. . . . 408 



The , First International Congress of Anat- 

 omists 499 



Magnetic and Allied Observations during the 

 Total Solar Eclipse: Dr. L. A. Bauer 411 



A National Conference of Trustees of Ameri- 

 can Colleges and Universities 412 



The Harvey Society 413 



Scientific Notes and News 413 



University and Educational Neios 416 



MSS. inteudedfor publication aud books, etc., intended 

 tor review should be sent to the Editor of Science, Garri- 

 son-on-Hudson, N. Y. 



THE PROGRESS OF PHYSICS IN THE 

 NINETEENTH CENTURY. 



II. 



DIFFRACTION. 



Though diffraction dates back to Gri- 

 maldi (1665) and was well known to New- 

 ton (1704), the first correct though crude 

 interpretation of the phenomenon is due to 

 Young (1802, 1804). Independently Fres- 

 nel (1815) in his original work devised 

 similar explanations, but later (1818, 1819, 

 1826) gave a more rational theory in terms 

 of Huyghens's principle, which he was the 

 first to adequately interpret. Fresnel 

 showed that all points of a wave front are 

 concerned in producing diffraction, though 

 the ultimate critical analysis was left to 

 Stokes (1849). 



In 1822 Fraunhofer published his re- 

 markable paper, in which, among other 

 inventions, he introduced the grating into 

 science. Zone plates were studied by 

 Cornu (1875) and by Soret (1875). Row- 

 land's concave grating appeared in 1881. 

 Michelson's echelon spectrometer in 1899. 



The theory of gratings and other diffrac- 

 tion phenomena was exhaustively treated 

 by Schwerd (1837). Babinet established 

 the principle bearing his name in 1837. 

 Subsequent developments were in part con- 

 cerned with the improvement of Fresnel's 

 method of computation, in part with a 

 more rigorous treatment of the theory of 

 diffraction. Stokes (1850, 1852) gave the 

 first account of the polarization accom- 

 panying diffraction, and thereafter Ray- 

 leigh (1871) and many others, including 



