May 12, 1899.] 



SCIENCE. 



685 



(8) Professor A. S. Hathaway : ' A new method 

 of presenting tbe principles of the calculus.' 



(9) Professor E. H. Moore : 'On the subgroups 

 of abelian groups. ' 



(10) Me. Carl C. Engberg : ' A modification of the 

 theory of the characteristics of evolutes (prelim- 

 inary communication).' 



(11) De. L. E. Dickson : ' Certain universal invari- 

 ants of linear modular groups.' 



■(12) Dr. L. E. Dickson : ' Concerning the four 

 knovrn simple groups of order 25,920.' 



The following is a list of papers read at the 

 JSTew York meeting of the Society : 

 (1) Dr. J. I. Hutchinson : 'The asymptotic lines 



of the Kummer surface. ' 

 {2} Dr. L. E. Dickson : ' The known finite simple 



groups. ' 



(3) Me. E. B. Wilson : ' Note on functions satisfy- 

 ing the equation 



<l>{x)<p{y)=^{x-\-y).' 



(4) Dr. a. S. Chessin : ' On the differential equa- 

 tion of dynamics. ' 



(5) Professor Charlotte Ang as Scott: 'A 

 proof of Koether's fundamental theorem.' 



(6) Dr. G. p. Starkweather : ' Non-quaternion 

 systems containing no skew units. ' 



(7) Professor E. Gouesat: ' Sur la definition 

 generale des fonctions analytiques d'apres 

 Cauchy. ' 



(8) Peofessor F. JMoeley : ' The value of 



P 



{log 2 cos ip)"'f'd<p.' 



(9) Professor E. "W. Brown: 'An elementary 

 illustration of the connection between the current 

 and the height of the water in a tidal estuary.' 



(10) Dr. W. M. Strong : ' Tlie determination of 

 non-quaternion systems in six units. ' 



(11) Peofessor E O. Lovett : 'Curves of mul- 

 tiple curvature. ' 



(12) Professor James Pierpont : 'Elliptic func- 

 tions. ' 



(13) Me C. J. Keysbr : ' On a definitive property 

 of the covariant. ' 



The summer meeting of the Society will be 

 held at the State University of Ohio, Columbus, 

 Ohio, on Friday and Saturday, August 2.5th and 

 26th, in affiliation with the meeting of the 

 American Association. 



F. N. Cole, 

 Secretary. 

 Columbia University. 



THE NEW YORK ACADEMY OF SCIENCES — SUB- 

 SECTION OP anthropology and 

 psychology. 



A REGULAR meeting of the sub-section was 

 held April 24th, in association with the Anthro- 

 pological Club. 



The first paper was read by E. A. Gerrard, 

 and gave methods for the study of emotional 

 expression as found in literary compositions. 

 The relative emotional values of the different 

 parts of speech, of different sentence lengths, 

 and other variations in the kind of language 

 used and in its arrangement, were discussed 

 and illustrated by curves derived from a num- 

 ber of writings. 



S. I. Franz presented some results of 

 experimental investigations of visual after- 

 images. The latent period increases as the 

 area of stimulation decreases, but decreases as 

 the intensity and duration of stimulation in- 

 creases. The duration of the after image in- 

 creases with any increase in the intensity, 

 duration and area of the stimulation. The 

 after-image of the colors in the middle of the 

 spectrum is not more intense than that of the 

 extreme colors if the intensity of the colors is 

 first equalized. The degree of attention is of 

 the first importance in determining the dura- 

 tion of the after-image. Retinal transference is 

 not real ; its apparent reality is due to the im- 

 possibility of distinguishing the fields of vision 

 of the two eyes. 



J. R. Swantou discussed the structure of the 

 Chinook language. Discourse in this language 

 shows great lack of subordination, its short 

 sentences following each other without connec- 

 tives. The verbs are aggregations of many 

 pronouns added to a short stem. They serve 

 in this way to epitomize the whole sentence, 

 object and indirect object, as well as sub- 

 ject. 



Stansbury Hagar read a paper on the Astro- 

 nomical Cosmogony of the Peruvians. The 

 pajjer aimed to show the large amount of as- 

 tronomical knowledge possessed by the Peru- 

 vians and the intimate relations between their 

 ritual and politieal life and their astronomy. 

 Charles H. Judd, 

 Secretary. 



