ITS PHYSICAL, CHEMICAL, AND STRUCTURAL CHARACTERS. 247 



parts of haemoglobin treated with hydrochloric acid yield about 4 parts of 

 hydrochlorate of hiematin (Fig. 114) and 90 parts of albumen. Iliematin 

 was erroneously supposed to be the true coloring material of the blood by 

 Berzelius, Mulder, Let-ami, Lehmanu, and others. According to Hoppe- 

 Seyler, its composition is represented by the formula CggH^Fe.jNgO^. When 

 dried it forms an amorphous bluish-black, or on being rubbed down, reddish- 

 brown powder. It withstands without decomposition a temperature of 350, 

 but above that point, carbonizes. It is insoluble in alcohol, water, ether, or 

 chloroform, but dissolves readily in acids and alkalies, and in acidified 

 alcohol, by which last it is freed from the albuminous compound. When 

 treated with sulphuric acid, the iron can be wholly withdrawn, and the 

 hrematin thus obtained, so far differs from ordinary hrematin, that whilst it 

 is insoluble in dilute acids, it presents the important chemical feature of 

 being polymeric with bilirubiu, or coloring matter of the bile, as shown by 

 the following formulae : 



C 96 H 51 N 6 Fe 3 18 + 3HO == 3(C 32 H 18 N,,0 6 ) + 3FeO. 



Hiematin. Bilirubin. 



Teichmann's Ha-mln crystals, which are identical with Lehmauu's H(e ma- 

 tin crystals (Fig. 115), Virchow's Hicmatoidui crystals, and Preyer's Hccma- 

 toin crystals, are all products of the decomposition of Haemoglobin. Preyer 

 has described two other crystalline compounds he has obtained from blood, 



FIG. 114. 



FIG. 115. 



TZ9* iffe 





Heemin Crystals, by Teicli- 

 iriann, in Hydrochlorate of 

 Hseinatin. 



Rhombic Crystals of Hydrochlorate of Hamiatiu, obtained by Lehraaun's method. They are ob- 

 tained when blood is subjected to the action of a mixture of 1 part of alcohol, 4 parts of ether, and 

 l-16th of oxalic acid, and appear as thin brownish and brownish-green, striated, transparent crystal- 

 line lauiin;e, often curiously twisted upon their long axes, and soon spontaneously changing into flat 

 rhombic octahedra. 



Hcematochlorin and Hcematolutein; and four non-crystalline substances 

 Methrcmoglobiu, Hrcmatiu, Hsemathiou, and Hseruatiuin. The formation 

 of the Hfemin crystals of Teichmaun is important in a medico-legal point of 

 view, since they can be obtained from a very minute speck of blood. The 

 best method is to triturate the supposed dry blood-spot with a little common 

 salt, and to add glacial acetic acid. The mixture is then to be warmed till 

 bubbles appear, and set aside to cool. If blood be present, numerous hrerain, 

 or hydrochlorate of luematin crystals appear in the form of rhombic tablets, 

 often arranged in stars or crosses of red, brown, or black color, becoming 



