OXYH^MOGLOBIN. 273 



netic (GAMGEE l ) . On passing an electric current through an oxyhaemo- 

 globin solution, the pigment first separates unchanged at the anode in a 

 colloidal but still soluble form, and is then gradually transferred to the 

 cathode in the colloidal state (GAMGEE 2 ). This transportation of the 

 colloidal haemoglobin may also be made to take place through an animal 

 membrane or through parchment paper. According to GAMGEE, the 

 haemoglobin probably exists in such a colloidal condition in the blood- 

 corpuscles. 



Oxyhaemoglobin has been obtained in crystals from several varieties 

 of blood. These crystals are blood-red, transparent, silky, and may be 

 2-3 mm. long. The oxy haemoglobin from squirrel's blood crystallizes 

 in six-sided plates of the hexagonal system; the other varieties of blood 

 yield needles, prisms, tetrahedra, or plates which belong to the rhombic 

 system. 3 The quantity of water of crystallization varies between 3-10 

 per cent for the different oxybaemoglobins. When completely dried 

 at a low temperature over sulphuric acid the crystals may be heated 

 to 110-115 C. without decomposition. At higher temperatures, some- 

 what above 160 C., they decompose, giving an odor of burnt horn, 

 and leave, after complete combustion, an ash consisting of oxide of 

 iron. The oxyhaemoglobin crystals from difficultly crystallizable kinds of 

 blood, for example from such as ox's, human, and pig's blood, are 

 easily soluble in water. The oxyhaemoglobins from easily crystallizable 

 blood, as from that of the horse, dog, squirrel, and guinea-pig, are soluble 

 with difficulty in the order above given. The oxyhaemogiobin dissolves 

 more easily in a very dilute solution of alkali carbonate than in pure water, 

 and this solution may be kept. The presence of a little too much alkali 

 causes the oxyhaemoglobin to quickly decompose. The crystals are 

 insoluble in absolute alcohol without decolorization. According to 

 NENCKi, 4 it is hereby converted into an isomeric or polymeric modifica- 

 tion, called by him parahoemoglobin. Oxyhaemoglobin is insoluble in 

 ether, chloroform, benzene, and carbon disulphide. 



A solution of oxyhsemoglobin in water is precipitated by many metallic 

 salts, but is not precipitated by sugar of lead or basic lead acetate. On 

 heating the watery solution it decomposes at about 70 C., and splits 

 off protein and haematin when sufficiently heated. It is also readily 



1 Proceedings of Roy. Society, 68. 



2 Ibid., 70. 



3 The observation of Uhlik (Pfliiger's Arch., 104) that the haemoglobin from horse- 

 blood can also crystallize in hexagonal six-sided plates seems to be due to the fact that 

 he had haemoglobin and not oxyhaemoglobin. 



4 Nencki and Sieber, Ber. d. d. chem. Gesellsch., 18. According to Kriiger (see 

 Biochem. Centralbl., I, 40, 463) haemoglobin is somewhat changed by alcohol as well 

 as by chloroform. 



