496 RECORDS. 



Dr. Max Meyer, 159 West 103d street. 



William L. Mason, 170 Fifth avenue. 



William Wicke, First avenue and 31st street. 



Edward R. Hewitt, 119 East i8th street. 



Charles H. Judd, New York University. 



Fred W. Franklin, 700 West End avenue. 



John I. D. Bristol, i Madison avenue. 



Rudolph Keppler, 28 West 70th street. Life member. 



The proposed by-laws, submitted to the Academy for adop- 

 tion, were adopted with two slight amendments, and will appear 

 printed in Annals, Vol. XII, No. i. 



After certain announcements by the Secretary in reference to 

 new plans, the Academy adjourned. 



Richard E. Dodge, 



Secretary. 



SECTION OF ASTRONOMY AND PHYSICS. 



December 5, 1898. 



The meeting was called to order at 8:15 P. M. by the Chair- 

 man, Mr. P. H. Dudley; 24 members and guests being present. 

 The minutes of the last meeting were read and approved. 



Mr. Wallace Goold Levison presented a paper A System 

 OF Classification of the Fluorescent and Phosphorescent 

 Substances, in which he classified as phosphorescent all those 

 substances that give out rays of shorter wave-length than that 

 of the rays they have previously received ; and as fluorescent, 

 all those substances that give out rays of greater wave-length 

 than those they hav^e received. The system was amplified by 

 an arrangement of substances under headings with reference to 

 the circumstances under which they phosphoresced or fluo- 

 resced. The classification was very clearly shown by lantern 

 slides of charts on which all phosphorescent and fluorescent 

 substances were set dow^i, and in addition, remarks about their 

 behavior under various circumstances. This classification has 

 required much labor for its preparation, and at the conclusion 



