1880.] 



Colouring-matters of Human Urine. 



225 



a most remarkable series of bands, in addition to that at F. The 

 experiment has been repeated several times, with, an uniform result. 



The fresh defibrinated blood of the sheep is treated with alcohol and 

 sulphuric acid (2 parts H 2 S0 4 to 35 alcohol) and filtered, more alcohol 

 being afterwards added (if necessary) to help the nitration. This dark- 

 red filtrate gives the spectrum of acid haematin, which is seen in sp. 9, 

 Chart III, and which gives the bands of haemochromogen (reduced 

 haematin) with sulphide of ammonium. It is put into a narrow 

 and deep beaker, some fragments of pure zinc and sulphuric acid 

 being added in sufficient quantity to develop a reaction, and a gentle 

 heat is applied to the water-bath over which the beaker is placed. 

 When the action has ceased the fluid is filtered, when it is seen to 

 have become of a much lighter colour. (Sp. 10.*) It is then 

 put into a separating funnel, diluted with water, and shaken with 

 chloroform. The chloroform takes up the pigment, forming a dark- 

 red solution ; on separating this off and filtering it, and then distilling 

 the chloroform, a dark-brown pigment is left. It is soluble in alcohol, 

 with a rich colour, and this gives sp. 11, Chart III, in a moderately 

 shallow layer. (Compare 7 and 8, Chart I.) 



Ammonia slightly alters the position of the bands, when added to 

 the alcoholic solution, bringing some of them slightly nearer the red 

 end ; narrowing and bringing the band at F near the red, but not 

 causing it to disappear. Caustic soda produces the same effect as am- 

 monia, sp. 12, Chart III (colour of solution, orange). Zinc chloride 

 produces almost the same change, sp. 13, Chart III. (Cf. action on 

 urobilin.) The chloroformic solution of this pigment gives sp. 14, 

 Chart III. 



On comparing these spectra with those of the urinary pigment, 

 uroheematin, it is seen that they are identical band for band, and the 

 description of the reactions with other reagents given by that pigment 

 will apply exactly to this one. 



On looking at Preyer'sf map of " iron- free haematin " a likeness to 

 the present pigment is noticed, but they are different bodies, and the 

 action of sulphuric acid aided by heat had nothing to do with the 

 result ; for we can not only prove that a different pigment is produced 

 under those circumstances, but urohaematin can be prepared in a 

 different manner, in which the influence of sulphuric acid aided by 

 heat is completely excluded. 



If the solution of hasmatoin be prepared as before, and it is then 

 shaken with chloroform and water in a separating funnel, the chloro- 

 form will take up the haematoin, for which I find it is a perfect solvent, 

 and again leave it, after it has been distilled off, in a neutral state. 



* Cf. action of sulphuric acid on the natural pigment, Chart I, 12. It is pro- 

 bably these bands that Hoppe-Seyler mentions, 

 f " Die Blutkrystalle," Tafel I, 15. 



