CONTENTS 
Page 
Mathematics. — The Average of an Analytic Functional . By N. Wiener 253 
Physics. — On the Calculation of the X-Ray Absorption Frequencies of the 
Chemical Elements By W. Duane 260 
Physics. — On the Calculation of the X-Ray Absorption Frequencies of the 
Chemical Elements (Second Note) By W. Duane 267 
Mathematics. — Semi-covariants of a General System of Linear Homo- 
geneous Differential Equations By E.B. Stouffer 273 
Mathematics. — An Algorism for Differential Invariant Theory ... 
ByO. E. Glenn 276 
Chemistry. — The Effect of Temperature and of the Concentration of 
Hydrogen Ions upon the Rate of Destruction of Antiscorbutic 
Vitamin (Vitamin C) 
By H. C. Sherman, V. K. La Mer and H. L. Campbell 279 
