V. — The Magnetic Rotary Dispersion of Solutions of Anomalous 

 Dispersing Substances^ 



BY FRED J. BATES 



BecquereP in 1880 observed the anomalous rotary dispersion 

 in oxygen. Others have failed to verify his results. In 1898 

 Macaluso and Corbino^ observed it in sodium vapor. They found 

 that the rotation increased with great rapidity as the absorption 

 band was approached, attaining a maximum in the edge of, and 

 dropping to a small positive rotation in the interior of, the band. 

 Zeeman* has also studied this phenomenon and finds for sodium 

 vapor, not too dense, a negative rotation in the interior of the 

 band. 



Biot/ Amdsten,'' Landolt,^ Nasini® and Gennari, Cotton" and 

 others found anomalous rotary dispersion in optically active 

 liquids, and in 1896^° Cotton observed a tendency toward what 

 he interpreted as an anomaly in ferric chloride, copper acetate, 

 and several other liquids, when they were placed in a magnetic 

 field. He found as an absorption band of a certain solution was 

 approached, going from red to violet, an increase in the rota- 

 tion above what would have been obtained had the solution been 

 transparent. In the solution of some other substance in which 

 he could approach a band from violet to red he found the rota- 



^Read before the American Association for the Advancement of Science 

 at its Washington meeting, 1902-3. 



2H. Becquerel, Compi. rend. 90, p. 1407. 1880. 

 3 Macaluso and Corbino, Compt. refid. 127, p. 548. 1898. 

 ^P. Zeeman, Proceedings Royal Academy of Amsterdam. May 31, 1902. 

 »M. Biot, Ann. de chhn. et de phys. (3) 10, p. 5. 1844. 

 «M. A. Arndslen, Ann. de chhn. et de phys. (3) 54, p. 403. 1858*. 

 7 H. Landolt, Beibl. 5, p. 298. 1881. 



8R. Nasini and G. Gennari, Zeitschr.f. physik. ChemieVd, p. 113. 1896. 

 •Cotton, Ann. de chem. et de phys. (7) 8, p. 347. 1896. 

 10 Cotton, L'Eclairage electrique 8, p. 162 and 199. 1896. 



265 



