SCIENCE 



Editokiai. Committee: S. Nkwcomb, Mathematics; E. S. Woodwaed, Mechanics; E. C. Pickbeino 



Astronomy; T. C. Mendenhall, Physics; E. H. Thueston, Engineering; Iea Eemsen, Chemistry; 



J. Le Conte, Geology; W. M. Davis, Physiography; O. C. Maesh, Paleontology; W. K. 



Beooks, C. Haet Meeeiam, Zoology; S. H. Scuddbe, Entomology; N. L. Beitton, 



Botany; Henry F. Osboen, General Biology; H. P. Bowditch, Physiology; 



J. S. Billings, Hygiene ; J. McKebn Cattell, Psychology ; 



Daniel G. Beinton, J. "W. Powell, Anthropology. 



Feiday, March 12, 1897. 



CONTENTS: 



A Lecture by EegnauU : Wolcott Gibes 409 



Professor Fontaine and Dr. Newberry on the Age of 

 the Potomac Formation: Lestee F. Waed 411 



The American Morphological Society: G. H. 

 Paekee 423 



Current Notes on Physiography : — 



Campbell on Drainage Modifications; Bitssell's 

 Glaciers of North America ; The Gohna Landslip : 

 W. M. DAVIS 437 



Otirrent Notes on Anthropology : — 



The Amerique Indians ; 30th Report of the Peabody 

 Institute; Pliocene Man in Britain: D. G. Bein- 

 ton 438 



Notes on Inorganic Chemistry: J. L. H 439 



Scientific Notes and Neios : — 



Revue de Mechaniqne ; General 440 



University and Educational News 444 



JXscussion and Correspondence : — 



Opportunities for Training in Physiology : H. P. 

 Bowditch. Note on Natrix Grohamii B. & G.; 

 Fkank C. Bakee, Feank M. Woodeuff. 

 Pseudo-Aurora Again: H. A. Hazen. Green- 

 land Glaciers: Edwaed H. Williams, je 446 



■Scientific Literature : — 



Letourneau on V Evolution de VEsclavage: D. 

 G. Beinton. The Geological and Natural History 

 Survey of Minnesota : C. E. Beecher. Shaw 

 on 3Iunicipal Government in Continental Europe : 

 Edwin O. Jordan 448 



■Societies and Academies : — 



Torrey Botanical Club : Edwaed S. Buegess. 

 The New York Academy of Sciences : "W. Hal- 

 LOCK. The Academy of Science of St. Louis: 

 Wm. Teelease 451 



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

 ifor review should be sent to the responsible editor, Prof. J. 

 MoKeen Cattell, Garrison-ou-Hudson, N. Y. 



A LECTURE BY BEGNAULT. 



"When a student at the College de France 

 in 1847 I heard a lecture by Victor Regnault, 

 of a part of which I send a copy. So far as 

 I know, it was never printed. The lith- 

 ographed copies were paid for by the 

 students themselves. I think that the 

 figures of prisms given (see plate) will have 

 something more than a purely historical 

 interest even now. 



WoLCOTT Gibes. 



Newpoet, January 27, 1897. 



Quelques physiciens out construits des 

 appareils au moyen desquels on peut ob- 

 server les raies du spectre sans qu'il soit 

 necessaire de se placer dans une chambre 

 obscure. 



A I'une des extremites d'un tuyau, Mr. 

 Dujardin place un diaphragme rectiligne ; 

 a I'autre extremite, un certain nombre de 

 prismes fixes dans la position du minimum 

 de deviation, en les disposant ainsi, il a 

 pour but de diminuer autant que cela est 

 possible, I'aberration de sphericite qui re- 

 sulterait de ce que les rayons incidents ne 

 sont pas paralleles. 



On obtient ainsi un spectre tres devi6, 

 mais cette disposition presente plusieurs in- 

 convenients ; la deviation minimum n'a 

 lieu que pour les rayons qui marchent dans 

 1' axe du tuyau ; de plus, quoi que I'on ait 

 diminue le plus possible I'epaisseur des 

 prismes les pertes de lumiere par reflexion 



