CONTENTS 
V 
An Electron Theory of EivEctric Conduction in Metals 
By Edwin H. Hall 307 
Static Deflection, Logarithmic Decrement and First Semi-Period of the 
Vacuum Gravitation NeedlE By C. Barus 313 
On a Comparison of the Relative Sensitiveness of Telephones 
By Carl Barm 326 
The Equilibrium Positions of the Vacuum Gravitation Needle in 1921 and 
1922 By Carl Barus 327 
Further Measurements of Stellar Temperatures and Planetary Radia- 
tion ByW.W. Cohlentz 330 
Proof of a Theorem Due to Heaviside By H. A. Lorentz 333 
Characteristics of a Short Wave Oscillator at Very Low Pressure 
By L. L. Nettleton 353 
The Refraction of X-Rays in Calcite By Bergen Davis and H. M. Terrill 357 
The Compressibility of Metals at High Pressures By P. W. Bridgman 361 
CHEMISTRY 
The Relation of Chalcedony to the Other Forms of Silica 
By E. W. Washburn and L. Navias 1 
The Action of Diazomethane on Uracil 
By T. B. Johnson, A. J. Hill and F. H. Case 44 
The Oxidation of Hydroquinol in the Presence of Aliphatic Amines ...... 
By Rolla N. Harger 57 
The Isolation of Pyrimidines from the Nucleic Acid of Tubercle Bacillus 
By T. B. Johnson and E. B. Brown 187 
The Thermal Ionization of Gaseous Elements at High Temperatures: 
A Confirmation of the Saha Theory 
By Arthur A. Noyes and H. A. Wilson 303 
GEOLOGY AND PALEONTOLOGY 
Coral Reefs of the Louisiade Archipelago By W. M. Davis 7 
Additional Studies in Arrested Evolution By R. Ruedemann 54 
New Forms of Life from the Silurian By R. Ruedemann 55 
The Average Chemical Composition of Igneous Rocks 
By F. W. Clarke and H. S. Washington 108 
Hesperopithecus, the First Anthropoid Primate Found in America 
By H. F. Osborn 245 
Recent Discoveries on the Antiquity of Man 
By H. F. Osborn and C. A. Reeds 246 
The Jades of Middle America By Henry S. Washington 319 
ZOOLOGY 
Skin Transplantation in Frog Tadpoles By W. H. Cole 29 
The Effect of Ether upon the Migration of the Scale Pigment and the 
Retinal Pigment in the Fish, Fundulus Heteroclitus . .By L. C. Wyman 128 
The Diverse Effects of Adrenalin upon the Migration of the Scale Pig- 
ment AND THE Retinal Pigment in the Fish, Fundulus Heteroclitus, 
Linn By A. S. Gilson, Jr. 130 
A Side Line in the Importation of Insect Parasites of Injurious Insects 
FROM One Country to Another By L. O. Howard 133 
Degeneration and Regeneration of the Lateral-line Organs in Amiurus 
Nebulosus By M. H. Chambers 186 
