1, Absorption-spectrum of a solution of oxyhremoglobin : 2, of a solution of haemoglobin ; 3, 

 of a feebly alkaline solution of methfrmoplobin ; 4, of a solution of hsematin in acid ether 

 (oxalic acid) ; 5, of an alkaline solution of hsematin ; 6, of an alkaline solution of haemo- 

 chromogen : 7, of an acid solution of urobilin ; 8, of an ammoniacal solution of urobilin, 

 after the addition of zinc chloride solution; 9, of a solution of lutei'n (ethereal extract 

 of the yolk of egg). 



437 



