66 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES — VOL, 13, NO. 4 
SCIENTIFIC NOTES AND NEWS 
Mr. A. E. Ruark gave the second of the series of lectures on the Quantum 
Theory at the Bureau of Standards on January 15, 1923. The quantum 
theory of spectroscopy and the Balmer series of hydrogen were discussed, 
the fundamentals of the theory being taken up in historical order. Mr. 
Ruark dealt with the two suppositions made by Bohr to explain the spectrum 
lines of hydrogen and the ionized helium atoms: 
(1) When the atom is not radiating, its single electron and its nucleus 
move in circles around their common center of gravity in conformity with 
ordinary dynamics, but the circles on which they can move are restricted to 
a finite number by the quantum condition that the angular momentum of the 
entire atom must be an integral multiple of h 27 where h is Planck’s con- 
stant; however, the nucleus is so heavy compared to the electron that it 
moves on a circle very small in comparison to the electronic orbit. 
(2) When the electron passes from one of these circles to another, where the 
system has less energy, the energy EF which is given up is transformed into 
a train of light waves of frequency v, where v is determined by the equation 
E = hy. Sommerfeld has extended the theory to the case of elliptic orbits, 
and has discussed the effect of change of mass of the electron due to its 
velocity thus obtaining an explanation of the fine-structure of the hydrogen 
and helium lines. Wilson and Sommerfeld have formulated the general 
quantum conditions which determine the discrete orbits possible in any sys- 
tem of particles with conditionally periodic motion; these include Bohr’s 
postulate concerning the angular momentum as a special case. Rubinowicz 
and Bohr have explained by the ‘‘correspondence principle” and the ‘‘prin- 
ciple of selection,” respectively, the absence of certain components of spec- 
tral lines, predicted by the above theories, so that satisfactory agreement 
between theory and experiment has been achieved in all respects. 
The Petrologists’ Club met on Tuesday, January 16. Mr. E.S. Larsen 
spoke on The probable hydrothermal origin of some corundum deposits. He 
divided the deposits into two classes, one in which solutions emanating from 
magmas introduced corundum together with other minerals into surrounding 
rocks; and another including those formed as veins in peridotites by solutions 
believed to be the last liquid of the peridotite itself. 
A Joint Resolution has been passed by the Senate and the House of Repre- 
sentatives reappointing Mr. Henry WHITE as a Regent of the Smithsonian 
Institution, appointing Mr. Freperic A. DeLANo to succeed the late JOHN 
B. Henperson, and Mr. Irwin B. LauGuuin to fill the vacancy caused by 
the expiration of the term of the late ALEXANDER GRAHAM BELL 
The National Gallery has now on exhibit in the Evans Room a collection 
of antique Etruscan, Greco-Roman and Byzantine jewelry, ancient glassware 
and pottery, dating from the Seventh Century, B.C. to the Eleventh Century, 
A.D., lent by the Archaeological Society of Washington. 
A considerable collection of antiquities from a pit house in Chaco Canyon, 
New Mexico, was presented to the U. 8. National Museum in January by 
the National Geographic Society and is now being cataloged in the Division 
of American Archeology. Objects from the subterranean dwellings are 
extremely rare, for the pit houses antedate most of the prehistoric Pueblo 
