260 IOWA ACADEMY OF SCIENCE 



Fournier d'Albe (Phys. Zeits., 14. 1306), The smallest quan- 

 tity of light that can be proved. 



Brown (Phys. Rev., (2) 1, 237), A method of production of 

 light-negative selenium. 



Brown (Proc. Iowa Acad. Sci., 20, 261), The similarity of elec- 

 trical properties in selenium and crystal contacts. 



Brown- (Electr. Rev., 62, 104), The electrical properties of se- 

 lenium. 



Brown and Sieg (Phys. Rev., N. S., 2, 487-493), The sensi- 

 bility curves for selenium. 



Grippenberg (Phys. Zeits., 14, 123 and 124), The refractive in- 

 dex of crystalline selenium. 



GuiUeminot (Compt. Rend., 156, 1155), The action of X rays 

 on selenium. 



Nicholson (Phys. Zeits.. 14, 1213; and Phys. Rev., Jan., 1914), 

 Electron theory of light-sensitiveness. 



PigulewsH (Beibl. z. d. Ann., 37, 72), The action of light on 

 the conductivity of sulphur. 



Ries (Zeits. f. Feinmechanik. 21, 61-62), Noteworthy properties 

 of selenium cells. 



Ries (Zeits. f. Feinmech., 21, 5-7), Influence of potential and 

 previous illumination on the fatigue of selenium. 



Ries (Monograph on selenium and its application. 189 pp. 

 Beibl., 33, p. 627). 



Stebbins (Pop. Astro.. 21, 1-9), The period and variation of Alpha 

 Orionis. 



Brown (Phys. Rev. N. S., 2, p. 153), The action of mercury vapor 

 on selenium. 



Brown and Sieg (Phys. Rev., N. S., 2, p. 487), A second paper 

 on the wave-length sensibility curves of selenium cells. 



1914. 



Brown (Phys. Rev. ; N. S., 4, 85-98), Isolated crystals of metallic 

 selenium and some of their physical properties. 



Brown and Sieg (Phil. Mag.. (6) 28, 497-508), The seat of light- 

 action in selenium and some new properties in matter. 



