134 On the Colouring -matters of Bile of Invertebrates. [Apr. 5, 



detailed, which showed beyond doubt that biliverdin was present, 

 and since in that case its origin could be traced to blood pigment, 

 the origin of biliverdin from blood pigment is demonstrated. 



The identity of stercobilin and hydrobilirubin got by the action of 

 nascent hydrogen on bilirubin is proved, and a difference between 

 them and febrile urobilin shown to exist. 



The statement that the absorption bands of sheep bile are the same as 

 those which occur in Gmelin's reaction is shown to be erroneous, and 

 a brief description of the method of isolating the colouring-matter of 

 sheep bile and the wave-lengths of its different solutions given. Chlo- 

 rophyll is shown to be absent. 



Under the head of urinary pigments, it is shown that the feeble 

 bands described by me in a former paper in the spectrum of febrile 

 urobilin are not due to impurities, but are as much part of the 

 spectrum as the band at F. Urohsematin, and its difference from 

 hsematoporphyrin and its pathological significance are discussed. A 

 simple method for the detection of indican in urine, some remarks on 

 uroerythrin, on a peculiar red colouring-matter in pale urine, some- 

 what like urrhodin, follow. The deductions from this part of the 

 paper cannot be very well given in the form of conclusions, and 

 are therefore scattered throughout the paper. 



A drawing of the microscopic structure of the liver of IAmax, 

 showing the enterochlorophyll within the liver cells, and maps of the 

 most important absorption spectra described, accompany the paper. 

 All readings are reduced to wave-lengths. 



