x ILEMIN 515 



To prepare hsemin Nencki and Sieber l take 400 grammes of red 

 blood-corpuscles, freed from serum and coagulated with alcohol ; add 

 1600 grammes of amyl-alcohol ; heat up; add 20 to 25 ccm. of 

 hydrochloric acid and simmer for 10 minutes. On cooling, crystals of 

 hsemin separate out ; the yield from 1 litre of blood is T5 to 3 grammes 

 of haemin crystals. Cloetta 2 and Rosenfeld 3 wash the blood-corpuscles 

 with sodium sulphate instead of with sodium chloride,- and extract the 

 alcohol coagulum with hot ethyl-alcohol containing sulphuric or oxalic 

 acid. The crystals formed on cooling are recrystallised from hot alcohol 

 containing HC1. Morner 4 coagulates diluted blood with sulphuric 

 acid, extracts with alcohol containing H 2 S0 4 , and after the addition of 

 HC1 heats the mixture up to the boiling-point. Schalfejew's 5 method 

 gives the purest ha3min and also the largest yield. He proceeds as 

 follows : To 1 volume of defibrinated blood, filtered through a linen 

 cloth, are added 4 volumes of glacial acetic acid heated up to 80; after 

 the mixture has cooled to between 55-60, heat up again at once to 80. 

 On allowing the mixture to cool crystals are formed; after 10-12 

 hours pour off supernatant fluid and wash the crystalline precipitate in 

 a high cylinder with 5-6 volumes of water ; after repeated washings 

 filter off the crystals and wash the crystals on the filter with water, 

 alcohol, and ether. One litre of blood yields 5 grammes of crystals 

 of the same size, and belonging to the triclinic system, forming thin 

 rhomboidal plates. 



The chemical nature of the crystals formed by Schalfejew's method 

 is discussed below. 



Hsemin forms microscopic, small brown plates, which are known as 

 Teichmann's crystals. 6 For medico-legal purposes, 7 it is customary to 

 mix some blood with a little sodium chloride and glacial acetic acid on 

 a microscopic slide, to cover the preparation with a cover-glass, to boil 

 the acetic acid, and to add 2 to 3 additional drops of acid. It is much 

 better to use potassium iodide, as the crystals are then much larger 

 (E. Wace Carlier). Haemin crystals show, according to Ewald, 8 a 

 distinct pleochroism, being either deep black or pale yellowish 



1 M. Nencki and N. Sieber, Ber.d. deutsch. chem. Ges. 17. II. 2270 (1884) ; and in 

 Schmiedeberg's Arch.f. exper. Path. u. Phcmn. 18. 401 (1884) ; 20. 325 (1885). 



2 M. Cloetta, ibid. 36. 349 (1895). 



3 M. Rosenfeld, ibid. 4O. 137 (1898). 



4 K. A. H. Morner, Malys Jahresber. /. Tierchemie, 27. 145 (1897). 



5 M. Schalfejew, Chem. Zentralbl. 18. 232 (from the Russian) (1885) ; Maly* 

 Jahresber. 15. 138 (1885). 



6 M. Schalfejew, Malys Jahresberichte, 15. 138 (1885). Compare also H. U. 

 Robert, Wirbeltierbl.ut in mikrokristallinischer Hinsicht, Stuttgart, Enke, 1901. 



7 F. Hoppe-Seyler, Med.-chem. Untersuch. p. 366 (1868) ; p. 523 (1870). 



8 August Ewald, Zeitschr. f. Biol. 22. 459 (1886). 



