NON-NITROGENOUS SUBSTANCES IN PLASMA. 1 59 
Apart from these somewhat doubtful differences in blood from different 
parts, the amount in 1 he blood remains almost constant, whatever the char- 
acter of the Pood, and e\ en during starval ion. The amount is Bomewhat in- 
creased as the result <>f heemorrhage,a result due either to accession of lymph 
(which contains a larger proportion of sugar than does blood), or to the 
operation, through the agency of the nervous system, causing an increased 
production of sugar from the liver-glycogen. If the amount of dextrose in 
the blood be artificially increased to more than a 1 unit 0*25 per cent, the excess 
passes off hy the urine. The amount is increased in diabetes, whether this be 
the result of the sugar puncture, of removal of pancreas, or of disease, 1 
hut even under these circumstances does not rise above 0'48 per cent. 
Fats. — These are present in plasma in small but variable quantity 
(0"2 to 0-5 or even 1 per cent.) L> heing most abundant after a meal 
containing much fat. The plasma or serum may then he milky from 
admixture with the fat-containing chyle. They are composed of the 
usual glycerides of fatty acids (palmitin, stearin, and olein). A small 
amount, 0'05-OT per cent., is in the form of soap. 3 It has been stated 4 
that there is a greater amount of fat (ether extract) in arterial than in 
venous blood, but this result is shown by Rohmann and Miihsam 6 to 
have been probably due to an error brought about by venous congestion, 
which affects the proportion of all the solids of blood as compared with 
the water. The fatty acids appear also to be partly in combination with 
cholesterin, forming cholesterin-esters, of which two have been separated 
by Hiirthle 6 in a crystalline form, namely, the olein and palmitin com- 
pounds, to the extent in horse serum of 0"08 and 0"06 per cent, respec- 
tively. Hiirthle further found that in the dog they were increased 
during inanition. The amount of cholesterin in serum or plasma is 
stated by Hoppe-Seyler to be about O05 gr. per 100 c.c. blood, 7 and is 
probably mainly in tire form of the fatty acid combinations just referred 
to, and not, as was formerly supposed, in the free condition (Hiirthle). 
Lipochrome. — -The yellow-colouring matter of serum is a lipochrome 
soluble in amylic and also in ethylic alcohol, but insoluble in turpentine. 
Its absorption spectrum shows two ill-defined hands, 8 one at the F and 
the other between the F and G Frauenhofer lines (Plate III., Fig. 
24). It resembles the lutein of Kiihne. 
Lactic acid. — The presence of sarcolactic acid as a regular con- 
stituent of normal blood plasma has been affirmed (0 - 017-0 - 054per cent, 
in dogs). 9 Salomon could only find it in blood from the dead body, not 
in that drawn during life, 10 but Irisawa confirms its existence in fresh 
blood (dog), and states that it is present to some extent in the cor- 
puscles as w T ell as in the plasma. 11 It is increased in blood which has 
1 Pavy, "On Certain Points connected with Diabetes"; Seegen, Wien. ined. Wchnschr., 
1886, S. 1561 and 1595. 
2 Ruling, Abhandl. d. math.-phys. '7. 0. /:. Sachs. Gesdlseh. d. Wissensch., 1874, S. 1, 
and Arb. a. d. physiol. Aiist. zu Leipzig. 
3 Hoppe-Seyler, Ztsehr.f. 'physiol. Chem., Strassburg, Bd. viii. S. 503. 
4 Bornstein, Diss.. Bre.slau, 18s7. 
5 Arch. f. d. ges. Physiol., Bonn, 1889, Bd. xlvi. S. 383. 
6 Ztsehr.f. physiol. Chem.. Strassburg, 1898, Bd. xxi. S. 331. 
7 Med. Chem. Untersuck., Berlin, 1866, S. 145. 
8 Kmkenberg, Sitzungsb.d.Jt no isch.Gesellsch.f. Med. u.Naturic, 1885, Sup) >1. Bd.xix.S.25. 
9 Gaglio (with Drechsel), Arch. f. Physiol., Leipzig, 1886, S. 400; Spiro, Ztschr. f. 
physiol. Chem., Strassburg, 1887, Bd. i. S. 110 ; Berlinerblau (with Nencki), Arch. f. 
exper. Path. v. Pharmakol., Leipzig. 1887, Bd. xxiii. S. 333. 
10 Virchow's Archiv, 1888, Bd. cxiii. S. 356. 
11 Ztsehr.f. physiol. Chem., Strassburg, 1893, Bd. xvii. S. 340. 
