408 THE LIVER. 



not be present in the liquid, because, as is well known, it gives a play 

 of colors, in green or blue, with the acid. 



HAMMARSTEN'S Reaction. An acid is first prepared consisting of 1 

 vol. nitric acid and 19 vols. hydrochloric acid (each acid being about 

 25-per cent). One volume of this acid mixture, which can be kept for 

 at least a year, is, when it has become yellow by standing, mixed with 

 4 vols. alcohol. If a drop of bilirubin solution is added to a few cubic 

 centimeters of this colorless mixture a permanent beautiful green color 

 is obtained immediately. On the further addition of the acid mixture 

 to the green liquid all the colors of GMELIN'S scale, as far as choletelin, 

 can be produced consecutively. 



HUPPERT'S Reaction. If a solution of alkali bilirubin is treated with 

 milk of lime or with calcium chloride and ammonia, a precipitate is 

 produced consisting of calcium bilirubin. If this moist precipitate, which 

 has been washed with water, is placed in a test-tube and the tube half 

 filled with alcohol which has been acidified with hydrochloric acid, and 

 heated to boiling for some time, the liquid becomes emerald-green or 

 bluish green in color. 



In regard to the modifications of GMELIN'S test and certain other 

 reactions for .bile-pigments, see .Chapter XV (Urine) . 



That the characteristic play of colors in GMELIN'S test is the result 

 of an oxidation is generally admitted. The first oxidation step is the 

 green biliverdin. Then follows a blue coloring matter which HEINSIUS 

 and CAMPBELL call bilicyanin and STOKVIS calls cholecyanin, and which 

 shows a characteristic absorption-spectrum. The neutral solutions of 

 this coloring-matter are, according to STOKVIS, bluish green or steel-blue 

 with a beautiful blue fluorescence. The alkaline solutions are green 

 and have no marked fluorescence, and show three absorption-bands: 

 one, sharp and dark, in the red between C and D, nearer to C; a second, 

 less well defined, covering D; and a third between E and F, near E. 

 The strongly acid solutions are violet-blue and show two bands, described 

 by JAFFE, between the lines C and E, separated from each other by a 

 narrow space near D. A third band between b and F is seen with dif- 

 ficulty. The next oxidation step after these blue coloring-matters is 

 a red pigment, and lastly a yellowish-brown pigment, called choletelin, 

 by MALY, which in neutral alcoholic solutions does not give any absorp- 

 tion-spectrum, but in acid solution gives a band between b and F. On 

 oxidizing cholecyanin with lead peroxide, STOKVIS l obtained a product 

 which he calls choletelin, which is quite similar to urinary urobilin, to- 

 be discussed later. 



1 Heinsius and Campbell, Pfliiger's Arch., 4; Stokvis, Centralbl. f . med. Wis- 

 sensch., 1872, 785; ibid., 1873, 211 and 449; Jaff<, ibid., 1868; Maly, Wien. Sitzungs- 

 ber., 59. 



