284 THE BLOOD. 



Based upon his investigations on the hsematinic acids and hsemopyrrol, 

 KUSTER 1 believes that the hsematin in part contains a group which is 

 readily changed into hsematinic acid but not into hsBmopyrrol, and a 

 part which can be changed into both hsematinic acid and pyrrol. 



PiLOTY 2 has published important investigations on the constitution 

 of hsematin and on the origin of KUSTER'S hsematinic acid. On warming 

 hsematoporphyrin with hydrochloric acid and tin chloride he obtained 

 three products, namely, hsemopyrrol, hsemopyrrol carboxylic acid, and 

 desoxyhsematoporphyrin. Ha?mopyrrol seems to be a unit body, and 

 is considered as 3-methyl-3-n-propyl-pyrrol. The hsematinic acid is 

 not formed from hsemopyrrol, but rather from the crystalline hsemopyrrol 

 carboxylic acid, CgH^NOg, which is formed in addition to hsemopyrrol in 

 the reduction of hsematoporphyrin, and which is transformed into hsematinic 

 acid, CgHgNO^ on oxidation. The desoxyhsematoporphyrin, C34H 38 X 4 O5, 

 which differs from the hsematoporphyrin by containing one atom of 

 oxygen less, yields on further reduction hsemopyrrol, hsemopyrrol car- 

 boxylic acid, and hsematopyrrolidinic acid. This last, which has not 

 been obtained pure, yields on further cleavage and oxidation, hsematinic 

 acid and a basic oil having a piperidine-like odor. These investigations 

 are in accord with KUSTER'S observations that a part of the hsematinic 

 acid is relatively easily split, while another part, on the contrary, is only 

 split with difficulty and gradually. They do not, on the contrary, agree 

 with the above statement of KUSTER that hsematin contains a group 

 which is readily changed into hsematinic acid but not into haemopyrrol, 

 and another group which yields hsematinic acid as well as pyrrol. 



Hsematin is amorphous, dark brown or bluish black. It may be 

 heated to 180 C. without decomposition; on burning.it leaves a residue 

 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 hsematin 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 



1 Beitrage zur Kenntnis des Hamatins, Tubingen, 1896; Ber. d. d. chem. Gesellsch., 



27, 30, 32, and 35; Annal. d. Chem. u. Pharm., 315, and Zeitschr. f. physiol. Chem., 



28, 40, 44, 54, and 55. 



2 Annal. d. Chem. u. Pharm., 366. 



