268 THE BLOOD. 



As rest-carbon MANCINI l designates that carbon which is not precipitated 

 by phosphotungstic acid. It originates in great part from the urea and sugar 

 and amounts to 0.076-0.089 gram in 100 cc. 



The pigments of the blood-serum are very little known. Besides 

 other pigments horse-serum, contains, as first shown by HAMMARSTEN, 

 bilirubin, which, according to RANG, is the only pigment of the serum of 

 this animal. This pigment occurs, although in small amounts, sometimes 

 in the serum of other animals and, according to BIFFI and GALLIC is 

 especially abundant in the blood of new-born. 



Urobilin is not, according to ATJCHE, ROTH and HERZFELD, a physi- 

 ological serum-pigment. Urobilinogen may occur in extraordinary 

 cases according to HILDEBRANDT/ and on allowing the blood in such 

 cases to stand urobilin may be formed therefrom. The yellow coloring- 

 matter of the serum seems to belong to the group of luteins, which 

 are often called lipochromes or fat-coloring matters. From ox-serum 

 KRTJKENBERG 4 was able to isolate with amyl alcohol a so-called lipo- 

 chrome whose solution shows two absorption-bands, of which one encloses 

 the line F and the other lies between F and G. 



The mineral bodies in serum and plasma are qualitatively, but not 

 quantitatively, the same. A part of the calcium, magnesium, and 

 phosphoric acid is removed on the coagulation of the fibrin. By means 

 of dialysis, the presence of sodium chloride, which forms the chief mass 

 or 60-70 per cent of the total mineral bodies, lime-salts, sodium car- 

 bonate, and traces of sulphuric and phosphoric acids and of potassium, 

 may be directly shown in the serum. 5 Traces of silicic acid, fluorine, 

 copper, iron, and manganese, are claimed to have been found in the serum. 

 As in most animal fluids, the chlorine and sodium are in the blood- 

 serum in excess of the phosphoric acid and potassium (the occurrence 

 of which in the serum is even doubted). The acids present in the ash 

 are not sufficient to saturate the bases found, a condition which shows 

 that a part of the bases is combined with organic substances, perhaps 

 proteins. This also coincides with the fact that the great part of 

 the alkalies does not exist in the serum as diffusible alkali compounds, 

 carbonate and phosphate, but as non-diffusible compounds, protein 

 combinations. According to HAMBURGER 37 per cent of the alkali of 

 the serum from horse-blood was diffusible and 63 per cent non-diffusible. 



1 Bioch. Zeitschr., 26 and 32. 



2 Hammarsten, see Maly's Jahresb., 8 (1878); Ranc, Compt. Rend. soc. biol., 62; 

 Biffi and Galli, Journ. de Physiol. et Path., 9 (1907). 



8 Auche, Compt. Rend. soc. biol., 67; Roth and Herzfeld, Deutsch. med. Wochenschr., 

 37; Hildebrandt, Munch. Med. Wochenschr., 57. 

 4 Sitz.-Ber. d. Jen. Gesellsch. f. Med., 1885. 

 6 See Giirber, Verhandl. d. phys.-med. Gesellsch. zu Wurzburg, 23. 



