1880.] Colouring-matters of Human Urine. 219 



delivery tube at the other end. The latter was allowed to dip almost 

 to the bottom of a test-tube containing a chloroformic solution of pure 

 bilirubin. The oxygen was purified by being passed through strong 

 sulphuric acid before entering the induction tube. After the ozone 

 had been passed into the solution for fifteen minutes, it got slightly 

 redder in colour, and it then gave a band covering D ; no other band 

 in shallow layer. The general absorption of the violet disappeared 

 gradually, and a band 8 became detached at F, the colour of the 

 solution becoming lighter at the same time. After longer action, the 

 colour became still lighter, and the band still remained. As no other 

 change took place, the action of the ozone was discontinued. The 

 b>and at F c read from wave-length 513 to 482, and when hydro- 

 chloric acid was added, it got darker, and gave the same reading, the 

 colour of the fluid becoming red. But when caustic soda was added, 

 the band read 507 to 480, and did not disappear. The pigment 

 formed was therefore not choletelin, for its band should have dis- 

 appeared with caustic soda, and if it had been febrile urobilin, it- 

 should have been displaced towards the red, instead of which it came 

 nearer the violet. But although the pigment produced by the action 

 of ozone on bilirubin was neither (apparently) choletelin nor febrile 

 urobilin, yet its action was somewhat similar to other oxidising 

 agents, in causing disappearance of the general absorption and the 

 formation of a pigment giving a band at F. 



Action of other Oxidising Agents on Bilirubin, 8fc. — The action of per- 

 manganate of potassium and peroxide of hydrogen on bilirubin is not 

 easily studied, from the difficulty experienced in getting them to act 

 on bilirubin ; for in chloroformic solution they will not do so, and when 

 made to act on solid bilirubin, their action is confined to the surface, 

 but on the whole, their tendency is to convert this pigment into 

 choletelin. Peroxide of hydrogen, when added to bilirubin under- 

 going oxidation, seems to advance the oxidation a stage, and then 

 stops short. Although it acts with difficulty on bilirubin, there are 

 other biliary pigments, such as those got in the alcoholic extract of 

 human bile pigments, with which peroxide of hydrogen gives a play of 

 colours, accompanied by the same alteration of spectrum which accom- 

 panies Grmelin's reaction ; but this will be referred to again. 



Action of Sodium Amalgam on Pure Bilirubin* — Bilirubin was sus- 

 pended in water, and a piece of sodium amalgam introduced. After a 

 few minutes a little of the fluid was taken and treated with hydro- 

 chloric acid, which caused the formation of brownish flakes ; these 

 were soluble in alcohol, forming a yellow fluid giving only general 

 absorption. At the end of an hour, the fluid was brownish in colour, 

 but lighter than it was at the end of half-an-hour. After nine and a 



* "Ann. Ch. Pharm.," elxi, 368; clxiii, 77, contain an account of Maly's ex- 

 periments on this subject. 



