248 IOWA ACADEMY OF SCIENCE 



1888 



Kalischer (Wied. Ann., 35, 1888, p. 397), Remarks on the ex- 

 periments of Uljanin and Righi. 



Righi (Beibl. z. d. Ann., 12, 683), The E. M. F. of selenium. 



Uljanw (Wied. Ann., 34, 241), E. M. F. of selenium in the 

 light. 



(Wied. Ann., 35, 836), Reply to Kalischer. 



1889 



Cornu (Compt. Rend., 108, p. 917 and 1211), The refraction 

 and absorption coefficient of selenium. 



Kalischer (Wied. Ann., 37, 528), The E. M. F. of selenium. 



Korda (Journ. de phys., 8, 1889, p. 231), Electrical action of 

 light on selenium. 



Righi (Wied. Ann., 36, 464), The E. M. F. of selenium. 



1890 

 Liesegang (Photogr. Archiv., 1890, p. 302), Photophon. 



Muthmann (Zeits, f. Kryst., 17, 336), Crystallographic studies 

 of certain modifications of sulphur and selenium. 



1891 



Bidwell (Electrician, 26, 213; Phil. Mag., 31, 250), Several 

 studies with selenium cells. 



Liesegang (1 Auflag. Ed. Liesegang), The problem of seeing 

 at a distance electrically. 



Minchin (Electrician, 26, p. 361; Phil. Mag., 31, 207), Experi- 

 ments with photo-electricity. 



Peterson (Zeits. f. Phys. Chem., 8, 601), The allotropic forms 

 of several elements. 



Muthmann (Zeits. phys. chem., 8, 396-397), Isomorphism with 

 sulphur. 



Retgers (Zeits. phys. Chem., 8, 72), Isomorphism of Selenium, 

 Sulphur and Tellurium. 



1892 



Mi mli in (Astron. and Astroph., 108, 702), photo-electric cells. 



