THE ISOMORPHISM AND THERMAL PROPERTIES 



OF THE FELDSPARS. 



PART I THERMAL STUDY, 



ARTHUR L. DAY and E. T. ALLEN. 



PART II OPTICAL STUDY, - J. P. 1DDINGS. 



WITH AN INTRODUCTION BY 

 GEORGE F. BECKER. 



Washington, D. C. : 

 Published by the Carnegie Institution of Washington. 



1905. 



