H^EMATIN HYDROCHLORIDE. 253 



teristic silky lustre and a dark blue colour. The crystals are allowed to settle 

 for at least twelve hours, and the clear dark brown mother-liquid is syphoned 

 off. The blue sediment, if care was taken to avoid the presence of any 

 blood clots in the defibrinated blood used in the preparation, is found on 

 microscopic examination to be entirely composed of crystals of haemin. It 

 is repeatedly washed by decantation with water; then thrown on a filter, 

 and, after renewed washing with distilled water, it is subjected to long-con- 

 tinued washing with spirit and ultimately with absolute alcohol. This washing 

 with alcohol must be continued so long as the alcohol assumes a brown colour, 

 and is a very long process. The blue mass remaining on the filter is ultimately 

 washed with ether and alcohol, and in the first instance is allowed to dry by 

 exposure to the air, and afterwards by heating to 115 C. 1 



It was stated by Schalfijew that by his process 5 grms. of pure hsemin can 

 be obtained from 1 litre of defibrinated blood. This yield, which would be 

 approximately equivalent to the theoretical yield, on the assumption that the 

 blood contains in the mean 1 2 per cent, of haemoglobin, is from my own experi- 

 ence never realised, 1 litre of blood yielding on the average 3 '5 grms. of 

 pure haemin. 



Physical and chemical properties. Whilst presenting in mass a blue 

 colour, and exhibiting, when floating in a liquid, a silky lustre, on micro- 

 scopic examination hsemin crystals appear dark brown elongated rhombic 

 plates and prisms belonging to the triclinic system. They are arranged 

 singly or in groups. They are sfcrongly doubly-refracting. They are 

 quite insoluble in water, alcohol, ether, or chloroform. 



When pure uniformly crystallised hsemin is boiled in pure glacial 

 acetic acid, the latter dissolves an appreciable quantity, assuming a dark 

 brownish-red colour. From this solution the hsemin is in great part de- 

 posited, on cooling, in perfect crystals, without any admixture with 

 amorphous substances. I find, however, that if the process of re-crystal- 

 lisation be repeated, the substance deposited on cooling consists of 

 haemin crystals mixed with some amorphous colouring matter. 



Haemin is very easily soluble in highly dilute solutions of the caustic 

 alkalies and their carbonates ; from these solutions hsematin is pre- 

 cipitated on the addition of an acid. If nitric acid be used as the 

 precipitant, the chlorine which had originally been combined with the 

 haematin, and which is now present in the filtrate as an alkaline 

 chloride, can be precipitated by silver nitrate. 



When hsemin crystals are heated, they remain unchanged up to 

 about 200 C. ; more strongly heated, they glow and leave an ash com- 

 posed of pure iron oxide. When pure lisemin is intimately mixed, as by 

 pounding, with pure concentrated sulphuric acid, hydrochloric acid is 

 liberated. 



Nencki and Sieber, who employed amyl alcohol in the preparation of 

 haemin, found that when prepared in this way the crystals contained amyl 

 alcohol, and that their composition corresponded to the formula (Co 9 Ho n N, 

 Fe0 3 .HCl) 4 C 5 H 9 .OH. 



The existence of a definite compound of haemin and amyl alcohol is, 

 however, doubted by Hoppe-Seyler. 2 



1 M. Schalfijew. I have not seen the original paper in the Journ. russlc. fiz.-cMm. 

 Obsh., St. Petersburg, 1885, S. 30-37. See abstracts in Ber. d. deutsch. chem. Gesellsch., 

 Berlin, 1885, Bd. xviii. (Referat Bd.), S. 232-233 ; also in Jahresb. u. d. Fortschr. d. Thier- 

 Chem., Wiesbaden, 1885, Bd. xv. S. 138. 



'-' " Ueber Blutfarbstoffe und ihre Zersetzungsproducte, " Ztschr. f. physiol. Chem., 

 Strassburg, 1882, Bd. x. S. 331. 



