FEB. 19, 1923 ANNOUNCEMENT 67 
ruins of the southwestern United States and traces of them have usually 
been entirely effaced. 
Mr. Grorce W. Hoover, chief of the Chicago Station of the Bureau of 
Chemistry, has been appointed chief of the newly created Drug Control 
Laboratory. Mr. M. W. Guover, who has been in charge of the Office of 
Drug Administration, has been recalled to the U. 8. Public Health Service, 
and Dr. L. F. Keser, chemist in charge of the Division of Drugs, has been 
promoted to the position of chemist in charge of special collaborating investi- 
gations and will direct the work involved in the enforcement of the Postal 
Fraud Law. 
Dr. A. Hrpuicka lectures every Friday afternoon, from 5 to 6 o’clock, at 
the Postgraduate school of the American University, 1901 F Street, on 
Human Variation, 1.e. variation in man’s characteristics, both physical 
and functional. ‘Those who may be interested are invited to attend. 
ANNOUNCEMENT 
Professor Sommerfield will give the following course of lectures at the 
Bureau of Standards at 4 p.m. as follows: 
Subject Date 
1. Introduction to Quantum Theory and Its Place in Modern Physics. .March 2 
2. Quantum Theory of Spectroscopy, Balmer Spectrum of H, etc...... 3 
3. Atomic Structure of the Chemical Elements....................... 5 
Tewave wheary and Quantum Theory .: i. \03 64.5.2 «cers =. caees 6 
5. The Significance of Quantum Numbers, azimuthal, radial, equa- 
PAG 5 HM EE HERG HK, 1 0. Fae h asi dete v te pos Awe cheats «eh aa niee Sanee 7 
bw weenan Pirect, Lueory of WMaonet0on., ... os seucuacec ass eee nace res 8 
¢. tane Structure in Complicated Spectra... 22.00.0006 5. ccs oe eee 9 
All persons interested are invited to attend. The Bureau of Standards is 
located at Connecticut Avenue and Van Ness Street, Washington, D. C. 
