OF ARTS AND SCIENCES. 823 



Mr. President and Gentlemen of the Academy, — I accept the medals 

 for Mr. Edison, and at his request I wisli to express his deep sense of 

 the great honor the Academy has conferred upon him. His work in the 

 tield of electric lighting has been the subject of prolonged litigation, and 

 at times he has had doubts in reading the opinions of learned experts 

 whether this work has been original or whether he has really contributed 

 anytliiiig to the world's progress. The recognition of his labors by the 

 American Academy of Arts and Sciences, regarded by Count Rumford 

 in his gifts as the coequal of the Royal Society of London, is therefore 

 especially grateful to him. Acting as his proxy, I thank the members of 

 the Academy for the distinction which they have by their votes conferred 

 upon him. 



The following papers were presented by title : — 



A Revision of the Atomic Weight of Magnesium. By Theo- 

 dore William Richards and H. G. Parker. 



A Revision of the Atomic Weight of Strontium. Second 

 Paper : The Analysis of Strontic Chloride. By T. W. Pdchards 

 and H. G. Parker. 



Contributions from the Gray Herbarium of Harvard Uni- 

 versity. New Series, No. 10 : — 1. Revision of the Genus Tridax. 

 2. Synopsis of the Mexican and Central American Species of the 

 Genus Jlilcania. 3. Revision of the Genus Zinnia. 4. Revision 

 of the Mexican and Central American Species of the Genus 

 Calea. 5. A Provisional Key to the Species of Porophyllum 

 ranging north of the Isthmus of Panama. 6. Descriptions of 

 new and little known Phanerogams, chiefly from Oaxaca. By 

 B. L. Robinson and J. M. Greenman. 



On the group of real Linear Transformations whose Invariant 

 is a real Quadratic Form. By Henry Taber. 



David Wo Cheever read an obituary notice of Richard M. 

 Hods:es. 



o 



Eight hnndred and eighty-fourth Meeting. 



October 14, 1896. — Stated Meeting. 



The President in the chair. 



The following deaths were announced : Thomas Tracy Bouvd 

 and Francis James Child, Resident Fellows ; George Brown 



