68 



SCIENCE 



[N. S. Vol. XXXIII. No. 837 



Constantine Demetrius Chroustehoff. Professor 

 of mineralogy, crystallography and petrography in 

 the St. Petersburg Academy of Medicine. St. 

 Petersburg. 



A. B. Fr. af Schult^n. Professor of chemistry 

 in the Alexander University at Helsingfors. 



SCIENTIFIC JOURNALS AND ARTICLES 

 The December number (volume lY, number 

 3) of the Bulletin of the American Mathe- 

 matical Society contains the following ar- 

 ticles: Eeport of the September meeting of 

 the San Francisco Section, by 0. A. Noble; 

 " A new proof of the theorem of Weierstrass 

 concerning the factorization of a power 

 series," by W. D. MacMillan; Eeview of 

 Kowalewski's Determinantentheorie, by Max- 

 ima Bocher; Eeview of Wright's Invariants 

 of Quadratic Differential Forms, by L. P. 

 Eisenhart; Eeview of Volume 4 of Sturm's 

 Geometrisehe Verwandtschaften, by Virgil 

 Snyder; "Notes"; "New Publications." 



The January number of the Bulletin con- 

 tains: Eeport of the October meeting of the 

 Society, by F. N. Cole ; Eeport of the Konigs- 

 berg meeting of the Deutsche Mathematiker- 

 Vereinigung; "On the saddlepoint in the 

 theory of maxima and minima and in the 

 calculus of variations," by E. G. D. Eichard- 

 son; "Note on identities connecting certain 

 integrals," by Louis Ingold; Eeview of Poin- 

 care's Gottingen Lectures, by G. D. Birk- 

 hofP; Eeview of Lorentz's Theory of Electrons 

 and of Wien's Elektronen, by E. B. Wilson; 

 " Shorter notices " : Lilienthal's Differential- 

 geometrie, Volume 1, by E. J. Wilczynski; 

 Boehm's Elliptische Funktionen, Part 1, by 

 L. W. Dowling; Dingeldey's Sammlung von 

 Aufgaben zur Anwendung der Differential- 

 und Integralrechnung, by E. W. Ponzer; 

 Murray's Calculus, by W. B. Carver; Crab- 

 tree's Theory of Spinning Tops and Gyro- 

 scopic Motion, by E. W. Brown; Loney's 

 Dynamics of a Particle and of Eigid Bodies, 

 by W. E. Longley; "Notes"; "New Publi- 

 cations." 



The Journal of Experimental Medicine be- 

 gins its thirteenth volume with the announce- 

 ment that it will hereafter be issued once a 



month instead of once in two months as here- 

 tofore. Two volumes will thus be issued each 

 year. No change is made in the price of sub- 

 scription. Dr. Benjamin T. Terry takes the 

 place of Dr. Eugene L. Opie as the associate 

 of Dr. Simon Flexner in the editorial control 

 of the journal. 



SPECIAL ARTICLES 



''■ VISUAL SENSATIONS FROM THE ALTERNATING 

 MAGNETIC field' 



The experiments reported by S. P. Thomp- 

 son in the Proceedings of the Royal Society, 

 B, 82 (557), pp. 396 ff., are of great impor- 

 tance, especially in view of the negative re- 

 sults which have been obtained in the several 

 earlier attempts to arouse sensations by sub- 

 jecting the head to the influence of a mag- 

 netic field. Previous experimenters seem, 

 however, to have used direct current, while 

 Thompson used alternating current. 



Thompson obtained his magnetic field from 

 a coil of 32 turns of stranded copper con- 

 ductor of .2 square inch equivalent cross sec- 

 tion, the coil having an internal diameter of 

 nine inches and a length of eight inches. 

 This coil was supplied with 50-cycle alter- 

 nating current, the maximal amperage being 

 180. The subject's head was inserted in the 

 coil, and under these conditions Thompson 

 and several others were able to obtain flicker- 

 ing light sensations which were especially 

 conspicuous in the peripheral part of the 

 visual field. The flicker was noticed even 

 when the eyes were open. Certain subjects 

 reported sensations of taste also. 



It occurred to me on reading Thompson's 

 report that the visual phenomenon might well 

 be due to idio-retinal light, under the sugges- 

 tion of the hum of the coil due to the alter- 

 nating current, and as Thompson mentions no 

 specific checks or precautions in his proced- 

 ure, it seemed worth while to repeat the ex- 



^ I am indebted to the persons mentioned in 

 this paper for their interest and participation in 

 the experiments, and especially to Professor J. B. 

 Whitehead and Mr. Henry C. Louis, without 

 whose cooperation the experiments would have 

 been impossible. 



