228 Dr. C. A. MacMunn. Researches into the [Dec. 16, 



giving the black band at F, caustic soda be added, it becomes yellow 

 in colour, and then gives a band, S, from wave-length 513 to 488. In 

 deep layers two otlier feeble bands are seen on the violet side of D 

 (Chart III, sp. 16*). When the alcoholic solution is treated with zinc 

 chloride and allowed to stand a few minutes, a narrow band is seen y 

 which is exactly the same band, as regards position and shading, as 

 that seen when solutions of febrile urobilin are treated with zinc 

 chloride. 



It would, therefore, appear that by the action of sodium amalgam 

 aided by heat, a colourless, or almost colourless, solution has been 

 obtained, which under the influence of sulphuric acid becomes orange- 

 red, and gives all the characters of febrile urobilin. The original 

 body acted upon with the sodium amalgam being identical with 

 choletelin and with normal urobilin. 



On the Action of Decolorised Bile on Haemoglobin. — Seeing that the 

 urinary pigments, at least such as are recognisable by means of the 

 spectroscope, can be produced with great ease from heematin, I was led 

 to think that perhaps haematin might be present in the bile, and as a 

 preliminary step to this inquiry I tried the effect of the colourless 

 constituents of the bile on haemoglobin. Ox-bile was treated with 

 rectified spirit, filtered, then well shaken with animal charcoal in a flask y 

 and again filtered ; as this filtrate showed some general absorption 

 of the violet, it was again decolorised. It was then evaporated almost 

 to dryness on the water-bath, and diluted with water ; the taste of the 

 solution was exceedingly bitter ; it was alkaline, and gave Pettenkofer's 

 reaction and its spectrum. To this fluid 3 cub. centims. of the 

 fresh defibrinated blood of a cat were added. The mixture was put 

 into a hot air-bath, and the bath heated to 110° F ; the mixture being- 

 stirred with a glass rod from time to time. It soon got darker in 

 colour, and then gave the spectrum of niethaemoglobin. The tempera- 

 ture of the bath was then raised to 180°, and the fluid got still darker 

 in colour. After longer action it became a fine crimson, and then gave 

 a band covering D, and one at F, sp. 18, Chart III. After longer- 

 action no further change took place. The same body can be produced 

 by the action of caustic soda in alcohol on haemoglobin. 



Action of Caustic Soda in Alcohol on Blood. — When fresh blood 

 (defibrinated) is treated with alcohol and caustic soda, the colour- 

 changes to dark red. If the blood so treated contain oxidised haemo- 

 globin, we get a band at D, and a feebler one at F ; but if it contain 

 reduced haemoglobin, and the reagent is added with exclusion of air,, 

 haemochromogen is formed at the same time. The spectrum got by 

 the action of the reagent on oxidised haemoglobin is evidently haematin,. 



* Another (doubtful) band may hare been present in red, its centre at ware-length 

 625 if so, the reduced pigment was passing by reduction into uroheematin, with which 

 three of its bands are coincident. 



