68 CHEMICAL CONSTITUENTS OF BODY AND FOOD. 
able from the nuclei and protoplasm of cells. They appear to be the 
most abundant of the proteid materials obtainable from cells. Xucleo- 
histon is the name of one of these separated from the thymus by Kossel 
and Lilienfeld. 1 The latter wives its percentage composition as 
C, 48-46; H, 7 ; X, 16-86: P, 3025; S, 07; 0, 23-95. The high 
percentage of phosphorus given here has never been obtained by me, 
from the numerous nucleo-proteids I have prepared and examined from 
the thymus and other organs. Details of these will be given under the 
heads of the various organs in question. In my own analyses, the 
amount of phosphorus rarely has exceeded 1 per cent. 
Xucleo-histon appears to be identical with the tissue fibrinogen of 
"Wooldridge, but this included a variable amount of lecithin. Other 
forms of the same substance have been called cytoglobin and preglobin by 
A. Schmidt.'-' "Wooldridge prepared his tissue fibrinogens from cellular 
structures, such as thymus and testis. The gland is finely minced and 
extracted with water for twenty-four hours. "Weak acetic acid is then added 
to the decanted extract, and after some hours the precipitated nucleo-proteid 
falls to the bottom of the vessel. This is the method used by Lilienfeld in 
the manufacture of nucleo-histon. Another method, which I have largely 
used, is to grind up the finely minced organ with about an equal volume of 
sodium chloride in a mortar. The resulting viscous mass (originally called 
hyaline substance by Eovida) is poured into excess of distilled water. The 
nucleo-proteid rises in strings to the surface of the water, where it may be 
skimmed off. 
Prepared by either method, the nucleo-proteid may be dissolved in 1 per 
cent, sodium carbonate solution. This solution injected intravascularly in 
small doses in dogs produces a hindering of the coagulation of the blood 
(Wooldridge's negative phase). In larger doses it produces intravascular 
coagulation." 
The lecithin found associated with "Wooldridge's tissue fibrinogens is 
variable in quantity, and does not appear to be organically united to them. 
After its removal the nucleo-proteids continue to exercise their most distinctive 
physiological characteristic, in producing intravascular clotting. 4 
In connection with nucleins and nucleo-proteids, it should be men- 
tioned that many of them contain iron, and, according to Bunge, 5 con- 
stitute in foods the normal supply of iron to the body; in this sense be 
has called them hsematogens. The composition of hamiatogen from egg- 
yolk be gives in percentages, which may be compared with the com- 
position of nuclein from yeast, as follows : — 
C 
H 
X 
O 
s 
p 
Fe 
1 Zischr.f. 2>hysiol. Chem.. Stra^sbuig, Bde. xviii. and xx. 
2 " Weitere Beitr. z. Blutlehre," Wiesbaden, 1895. 
3 Details with reference to the influence of nucleo-proteids on Mood coagulation are 
given in the article dealing with that subject. 
4 Halliburton and Brodie, Journ. Physiol., Cambridge and London, 1894, vol. 
xvii. ]>. 135. 
5 Ztschr. f. physiol. Chem., Strassburg, 1884, Bd. ix. S. 49. 
ematogen. 
Xud 
ein from Yeast 
4241 
40-81 
6-08 
5-38 
14-73 
15-98 
31-05 
31-26 
0-55 
0-38 
5-19 
6-19 
0-29 
