Physiology. — “On Serum-lipochrome’. (First part). By Prof. 
A. A. HijMANS VAN DEN Beren and Dr. P. Murren. 
(Communicated at the meeting at December 27, 1919). 
In a previous investigation') I gave evidence to show that the 
normal human blood-serum contains two pigments: bilirubin and 
a lipochrome. Prior to this, opinions about the materials that yield 
the colour of normal serum, were contradictory and confused. The 
French clinician GirBeRT e.g. believed that the colour of the human 
bloodserum was due exclusively to bile-pigment and that it never - 
contained lutein (lipochrome). The Italian researcher Zoya, on the 
other hand, asserted that bilirubin is never present in the serum of 
normal man, but that the yellow colour is owing to lutein. We 
suspect these clashing opinions to have arisen from unsuitable methods 
of separating the pigments. It is especially the extraction of a protein- 
rich fluid like blood-serum, by shaking with ether and similar solvents, 
that yields unsatisfactory and differing results. When, however, we 
precipitate the serum by an appropriate amount of alcohol most of 
the bilirubin will pass over into this fluid, while from the ensuing 
protein-precipitate the lipochrome can be readily extracted with ether. 
In this way we are enabled to separate both pigments from the 
serum. After having watched the fate of bilirubin under various 
circumstances*), an inquiry on lipochrome naturally suggested itself 
to us. 
Yellow pigments, which for the present may conveniently be 
termed “lipochromes”, have until recently been investigated chiefly 
by botanists*). Srokges*) and SorBy®) discovered that in the green 
parts of plants besides chlorophyl numerous yellow pigments are 
to be found. 
Prior to their findings carotin had already been separated from 
1) HiuMANs VAN DEN Beren u. Snapper. Deutsch. Arch. f. klin. Mediz. 110, 540, 1913. 
2) HiuyMANS vAN DEN Beren. Der Gallenfarbstoff im Blute. Leiden 1914. 
5) For the literature see T. Tammes. Flora 87, 205, 1900, and C. v. WisseLinen, 
Flora 107, 371, 1915. 
*) Srokes. Proc. Roy. Soc. 18, 144, 1864. 
5) Sorsy. Ibid, 21, 442, 1873. 
