METHOD OF OBTAINING HETELEMOGLOBIN CRYSTALS. 201 



An Easy Method of obtaining Methsemoglobin 

 Crystals for Microscopic Examination. 



By 



W. ». Halliburton, MVO., B.Sc, 



Assistant Professor of Physiology, University College, London. 



(From the Physiological Laboratory, University College, London.) 



Meth^moglobin is a derivative of the red colouring matter 

 of the blood, concerning which a number of theories have been 

 held. According to Sorby, 1 it is more highly oxygenated than 

 oxyhemoglobin; that is, it is a per-oxyhaemoglobin. Hoppe- 

 Seyler, 3 on the other hand, regards it as a sub-oxyhemoglobin, 

 as it can be obtained under conditions which remove at least 

 part of the oxygen of oxyhemoglobin. According to both these 

 views, however, the oxygen is regarded as being more firmly 

 combined with the haemoglobin than in the case of oxy- 

 hemoglobin. 



More recently, however, Hiifner and Kiilz 3 have advanced 

 a third theory concerning the constitution of methsemo- 

 globin, and that is that it contains the same amount of oxygen 

 as oxyhsemoglobin, only in a closer state of combination. 

 They are able to make this assertion from actual analyses; 

 and these analyses were possible, inasmuch as they succeeded 

 in obtaining methaemoglobin in a crystalline form. The 

 method of obtaining these crystals is as follows : 4 — Three or 

 four cubic centimetres of a concentrated solution of ferri- 



1 ' Quart. Journ. Micr. Sci.,' 1870, p. 400. 



2 'Zeit. Physiol. Chemie,' vol. ii, p. 150. 



3 ' Zeit. Physiol. Chemie,' vol. vii. 



4 G. Hiifner, " Ueber Krystallinisches Mcthiimoglobin vom Hunde," ' Zeit. 

 Physiol. Chem.,' Bd. viii, p. 366. 



VOL. XXVIII, PART 1. NEW SER. O 



