(Continued from page 3 of cover.) 



VOLUME 58. 



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



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

 Birkhoff, George D. and Langer, Rudolph E. — The Boundary Problems Associated 



with a System of Ordinary Linear Differential Equations of the First Order, pp. 49- 



128. In press. 

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



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

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

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



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

 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. 

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

 1923. $1.25. 



