(Continued front page 3 of cover.) 



VOLUME 58. 



1. Ames, A. Jr., Proctor, C. A., and Ames, Blanche. — Vision and the Technique of Art. 



pp. 1-47 28 pis. February, 1923. $3.75. 



2. BnuKHOFF, George D. and Langer, Rudolph E. — The Boundary Problems and Develop- 



ments Associated with a System of Ordinary Linear Differential Equations of the First 

 Order, pp. 49-128. April, 1923. S3.15. 



3. Vainio, Edward A. — Lichenes in Insula. Trinidad a Professore R. Thaxter Collecti. 



pp. 129-147. January, 1923. $1.00. 



4. Bridgm an, P. W. — The Effect of Pressure on the Electrical Resistance of Cobalt, Alumi- 



num, Nickel, Uranium, and Caesium, pp. 149-161. January, 1923. $.75. 

 6. Bridgman, P. W. — The Compressibility of Thirty Metals as a Function of Pressure and 

 Temperature, pp. 163-242. January, 1923. $1.70. 



6. Baxter, Gregory P., Weatherill, Philip F. and Scripture, Edward W., Jr. — A 



Revision of the Atomic Weight of Silicon. The Analysis of Silicon Tetrachloride and 

 Tetrabromide. pp. 243-268. February, 1923. $.75. 



7. Evans, Alexander W. — The Chilean Species of Metzgeria. pp. 269-324. March, 



1923 S1.25. 



8. Brues, Charles T. — Some New Fossil Parasitic Hymenoptera from Baltic Amber. 



pp. 325-346, March, 1923. S.65. 



9. Kenneixy, A. E. — Text or the Charter of the Academie Royale de Belgique, Trans- 



lated from the Original in the Archives of the Academie at Brussels, pp. 347-351. 

 April, 1923. $.40. 

 10. Hitchcock, Frank L. — On Double Polyadics, .vith Application to the Linear Matrix 

 Equation, pp. 353-395. May, 1923. SI. 1 5 



