SCIENCE 



Editoeial Committee : S. Newcomb, Mathematics ; E. S. Woodwaed, Mechanics ; E. C. Pickering, 



Astronomy; T. C. Mendenhall, Physics; R. 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. Scuddee, Entomology; C. E. Bessey, N. L. Beition, 



Botany; Henry F. Osborn, General Biology; C. S. Minot, Embryology, Histology; 



H. P. BoWDiTOH, Physiology; J. S. Billings, Hygiene ; J. McKeen Cattell, 



Psychology; Daniel 6. Beinton, J. W. Powell, Anthropology. 



Friday, June 10, 1898. 



CONTENTS: 



Oh Color-blindness : Peofessoe Ogden N. EOOD..785 



37*6 Opening of the New Laboratory for Physical 

 Chemistry in Leipzig: De. Harey C. Jones... 786 



Wireless Telegraphy 791 



Current Notes on Meteorology : — 

 Physiological Effects of Humidity ; Electric Search- 

 lights as Weather Signals ; Civil Service Examina- 

 tions for Posilio7is in the Weather Bureau ; False 

 Deio; Notes: R. DeC. Waed 793 



Ou/rrent Notes on Anthropology ; — 



Languages of Honduras; The Ruins of Mexico; 

 Ethnography of Cuba : Peofessoe D. G. Bein- 

 ton 795 



Astrophysical Notes : E. B. F 795 



Notes on Inorganic Chemistry: J. L. H 796 



Scientific Notes and News : — 



Lord Play fair ; The Imperial Institute; Tests of 

 Seeds by the U. S. Department of Agriculture; 

 General 797 



University and Educational News 801 



Discussion and Correspondence : — 



A Precise Criterion of Species : De. J. A. Allen. 

 A Necessary Correction: G. F. Andeews 801 



Scientific Literature : — 



Suess on ' La face de la terre :' J. B. WooD- 

 WOETH. Pilsbry's Catalogue of the Land Sitells of 

 America: T. D. A. Cockeeell. Bibliographia 

 Oeologica: F. B. Weeks 803 



Scientific Journals 809 



Societies and Academies : — 



Oeological Society of Washington : De. W. F. 

 MoESELL. Torrey Botanical Club : E. S. Bur- 

 gess. Section of Geology and Mineralogy of the 

 New York Academy of Sciences: Heinrioh 

 Eies. Botanical Seminar of the University of 

 Nebraska 810 



New Books 812 



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

 for review should be sent to the reaponaible editor. Profes- 

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



ON COLOR BLINDNESS. 

 On the Application of the Flicker Photometer 



to the Quantitative Study of Color Blindness. 



In the previous number of tliis Journal, I 

 gave a short account of one of the forms of 

 certain flicker photometers devised by my- 

 self, and now will still further illustrate its 

 use by detailing some experiments that 

 were made with it on persons more or less 

 color blind to red. The mode of proceed- 

 ing was as follows : Plates of deep red and 

 violet-blue glass were placed on opposite 

 sides of the prism and one of the lamps al- 

 lowed to remain stationary; the blue glass 

 was next to it. On the side of the movable 

 lamp the red glass was placed. In case, 

 then, the patient was more or less blind to 

 red light it would be necessary for him to 

 move up the lamp which furnished the red 

 light nearer to the prism, in order to cause 

 the flicker to disappear, than would- be the 

 case in normal vision. This experiment 

 having then been repeated by a person 

 with normal vision, the joint result fur- 

 nishes the means of measuring the amount 

 of red color blindness, it being, of course, as- 

 sumed in this procedure that the eyes of 

 the two experimeters are normal for blue 

 light. This determination being finished, 

 I replaced the red glass by green, the blue 

 glass remaining in its old position next to 

 the stationary lamp, and new measurements 

 were made as before by both persons in 

 order to test for green color blindness. 



