526 CHEMISTRY OF THE PEOTEIDS CHAP. 



I. a A624-A614 



III. /3 A5S4-A563 



A571-A563 darkest 



IV. y A543-A525 

 V. 8 A516-A485 



The so-called 'metallic spectrum' of hsematoporphyrin, first 

 described by MacMunn in 1889, and then by Hammarsten l and 

 Garrod, 2 Schulz obtained by adding zinc chloride to an ammoniacal 

 solution : 



III. a A589-A570 



IV. /3 A560-A526 



V. y A512-A501 (See below.) 



In acid solutions it possesses a spectrum with two well-marked 

 and several less distinct absorption-bands. The a-band lies between 

 C and D, close to D, while the second or /2-band is most intense half- 

 way between D and E ; its faint edge almost reaches D. 



a A597-A587 (Garrod 3 and Nebelthau 4 ) 

 ft A557-A541 



In alkaline solutions it shows four bands (Garrod, 2 Nebelthau, 4 and 

 Gamgee) : 



a Between C and D . . . A621-A610 

 P Between D and E, close to D . A590-A572 

 y Between D and E, close to E . A555-A528 

 8 Between b and F . . . . A514-A498 

 e Between h and H, and in strong solutions to K and beyond. 



All these bands may be shifted more towards the red or towards 

 the violet end of the spectrum, according to the amount of ammonia 

 or alkali present in the solution. In addition, the method of pre- 

 paring alkaline hsematoporphyrin also alters the spectrum. On the 

 addition of an alkaline zinc acetate solution the bands a and 8 

 disappear, while the bands /3 and y become sharper and more 

 intense. The e-band is seen in all hsematoporphyrin -solutions what- 

 ever the reaction may be, but it is more evident in alkaline solutions 

 (Gamgee). Hsematoporphyrin has been found in the urine of people 



1 Hammarsten, Skandin. Archiv. f. Physiol. 3. 319 (1892). 



2 Garrod, Journ. of Physiol. 13. 598 (1892). 



3 A. F. Garrod, ibid. 13. 603 (1892) ; 17. 349 (1895). 



4 E. Nebelthau, Zeitschr. /. physiol. Chem. 27- 324 (1899). (Full literature is 

 given.) 



