ANNOUNCEMENT OF MEETINGS OF THE ACADEMY AND 



AFFILIATED SOCIETIES^ 



Tuesday, May 7 : The Botanical Society, at 8 p. m. 



Thursday, May 9: The Washington Academy of Sciences, at the 

 George Washington Medical School, at 8.15 p. m. Program to be 

 announced later. 



Thursday, May 9: The Chemical Society. The regular meeting has 

 been replaced by the joint meeting with the Washington Academy, 

 May 15. 



Saturday, May 11: The Philosophical Society, at the Cosmos Club, 

 at 8.15 p. m. Program: 



A. Q. Tool, Bureau of Standards: The constitution of the gas ion. (Illustrated) , 

 L. A. Bauer, Department of Terrestrial Magnetism: Corresponding changes in 

 the earth's magnetic state and in solar activity, 1888-1916. (Illustrated). 



Wednesday, May 15: The Washington Academy of Sciences and the 

 Chemical Society, joint meeting at the Interior Department, 18th 

 and F Streets, at 8.15 p. m. Program: 



Arthur A. Notes, Massachusetts Institute of Technology: The determination 

 of crystal structure by x-rays. 



Saturday, May 18: The Biological Society, at the Meeting House, 

 Friends' School, 1809 I Street, at 8 p. m. Program: 



Dr. J. C. Merriam, Professor of Paleontology, University of California: Cave 

 hunting in California. 



> The proerams of the meetings of the afiGliated Societies will appear oa this page if sent to the 

 editors by the thirteenth and twenty-seventh of each month. 



