xiv CONTENTS. 



CHAP. PAGE 



XXII. THE SOLAR ATMOSPHERE ON THE NEW HYPOTHESIS .... 303 



XXIII. MORE TESTS THE SPECTRA OF SUN-SPOTS 310 



XXIV. SPECIAL TESTS WITH REGARD TO IRON . . 326 



XXV. TESTS SUPPLIED BY ECLIPSE OBSERVATIONS 354 



XXVI. THE BASIC LINES , 368 



XXVII. TESTS SUPPLIED BY THE PHENOMENA OF THE ARC 378 



XXVIII. APPLICATIONS OF THE HYPOTHESIS TO THE GENERAL PHENO- 

 MENA OF THE SUN 402 



INDEX . 450 



