OF ARTS AND SCIENCES. 515 



On the recommendation of the Rumford Committee, it was 

 Voted, To appropriate from the income of the Rumford Fund 

 the sum of two hundred and fifty dollars (-1250) to Professor 

 A. A. Michelson, of Chicago, for an investigation regarding dif- 

 fraction gratings. This is in addition to a sum of two hundred 

 and fifty dollars already appropriated by the Rumford Commit- 

 tee from the funds at its own disposal. 



The following papers were presented by title : — 



Contributions from the Gray Herbarium of Harvard Uni- 

 versity. New Series. No. XIH. — By B. L. Robinson. I. Re- 

 vision of the North American and Mexican Species of Mimosa. 

 II. Revision of the North American Species of Neptunia. 



An Inquiry into the Nature of Electrical Discharges in Air 

 and Gases. By John Trowbridge. 



On the Sources of Luminosity in the Electric Arc. By Henry 

 Crew and Olin H. Basquin. Presented by C. R. Cross. 



A Table of Atomic Weights. By Theodore William Richards. 



On the Cause of the Retention and Release of Gases occluded 

 by the Oxides of Metals. By Theodore William Richards. 



Edward Atkinson read a paper, entitled " The Basis of the 

 Science of Political Economy." 



The question of printing a table of atomic weights every year, 

 with T. W. Richards's corrections, was referred to the Committee 

 of Publication. 



E)ight hundred and ninety-ninth Meeting. 



April 13, 1898. 



The Academy met at the house of Augustus Lowell. 



The President in the chair. 



The President announced the death of Sir Henry Bessemer, 

 Foreign Honorary Member. 



The following papers were read : — 



The Theory of Coral Reefs. By Alexander Agassiz. 



Occurrence of Native Copper at Franklin Furnace, New 

 Jersey. By John E. Wolff. 



