292 THE BLOOD. 



consisting of iron oxide. It is insoluble in water, dilute acids, alcohol, 

 ether, and chloroform, but it dissolves slightly in warm glacial acetic acid. 

 Hsematin dissolves in acidified alcohol or ether. It easily dissolves in 

 alkalies, even when very dilute. The alkaline solutions are dichroic; 

 in thick layers they appear red by transmitted light and in thin layers 

 greenish. The alkaline solutions are precipitated by lime- and baryta- 

 water, as also by solutions of neutral salts of the alkaline earths. The 

 acid solutions are always brown. 



An acid haematin solution (spectrum Plate, 4), absorbs the red part 

 of the spectrum only slightly and the violet parts strongly. The solu- 

 tion shows a rather sharply defined band between C and D, whose posi- 

 tion may change with the variety of acid used as a solvent. Between 

 D and F a second, much broader, less sharply defined band occurs, which 

 by proper dilution of the liquid is converted into two bands. The one 

 between b and F, lying near F, is darker and broader; the other, between 

 D and E, lying near E, is lighter and narrower. Also by proper dilution 

 a fourth very faint band is observed between D and E, lying near D. 

 Haematin may thus in acid solution show four absorption-bands; ordi- 

 narily one sees, distinctly, only the bands between C and D and the broad, 

 dark band or the two bands between D and F. In alkaline solution, 

 haematin (spectrum Plate, 5), ishows a broad absorption-band, which 

 lies in greatest part between C and D, but reaches a little over the line 

 D toward the right in the space between D and E. As the position of 

 the hsematin bands in the spectrum is quite variable, the exact wave- 

 lengths corresponding thereto cannot be given exactly. 



Haemin, H^MIN CRYSTALS, or TEICHMANN'S CRYSTALS. Haemin is 

 formed, as generally admitted, by the replacement of an HO group by 

 chlorine in the haematin, and is the starting point in the preparation of 

 the latter. 



The statements as to the composition of haemin differ quite considerably, 

 and various haemins have been accepted, which is partly due to the fact, 

 as first shown by NENCKI and ZALESKI, that haemin combines with acid 

 and alkyl radicals and can also give addition products with other 

 bodies. Thus for example the methylhaemins, carefully studied by 

 KUSTER, especially monomethylhaemin, is produced in the preparation 

 of haemin according to MORNER'S method (see below) by means of methyl 

 alcohol. These behaviors have been further explained by the work 

 of numerous investigators, especially by KUSTER, and most investigators 

 generally admit that only one haemin exists whose general formula is 

 C34H330 4 N 4 FeCl. According to PILOTY the formula is C34H 3 204N 4 FeCl 

 while PIETTRE and VILA 1 deny this formula and claim to have 



1 Nencki and Zaleski, Zeitschr. f. physiol. Chem., 30; Nencki and Sieber, Arch, 

 f. exp. Path. u. Pharm., 18 and 20, and Ber. d. d. chem. Gesellsch., 18; Schalfejeff 



