COLOKING ORGANIC SUBSTANCES. 101 



just mentioned, and which are constantly falling off from the body 

 as excrementitions. 



THIRD DIVISION. 



Coloring or Colored Organic Substances. 

 Under this head are included 



1. Haematine the coloring matter in the blood-corpuscles. 



2. Biliverdin in the bile. 



3. Melanine in melanotic deposit, &c. 



4. Urrosacine in urine. 



1. The urine-pigment is of no importance in histology, and will 

 be merely mentioned here. 



2. The bile-pigment, also, will be but briefly alluded to. The 

 biliverdin is the green, the cholepyrrhin (Berzelius) or biliphaein 

 (Simon) is the brown, and the bilifulvin is the yellow, coloring-matter 

 of the bile. The last is entirely converted into haematoidine (see p. 

 102), and is formed in stagnant bile as haematoidine is in stagnant 

 blood. 



The greenish color of the feces (as in diarrhoea) is generally due 

 to an admixture of decomposed blood, and rarely to the presence of 

 biliverdin. Bile-pigment is, however, never entirely absent from 

 the feces, except in some rare cases of icterus. Nothing is known 

 of the origin of the bile-pigment. It is probably not formed in the 

 liver. (Lehmann.) 



In diseases, bile-pigment may be found in the urine, in the fluid 

 of the areolar tissue, and even in the sweat and the saliva. It is 

 also deposited in all the fluids of the eye; and in the sclerotic coat. 

 Sometimes, indeed, the saturation of the organism is so extreme as 

 to color the cartilages, ligaments, bones, and even the nerves. 



3. ffcematine. (C 44 H 22 N 3 6 Fe.) 



Hsematine occurs only in the red corpuscles of the blood of the 

 higher animals, and gives the latter its bright red color. It consti- 

 tutes 1.675 per cent, of the moist corpuscles, and about .73 per cent, 

 of the whole blood; but this substance obtained by the chemist is 

 not the coloring-matter as it naturally exists in the corpuscles, but 

 is a product of its metamorphosis. It is naturally dissolved in the 

 globuline in the corpuscles, but can be obtained only in its coagu- 



