PROTOPLASM AND CELLS. 81 
been analysed by Reinke 1 and Krukenberg, 2 and their observations con- 
firm what has just been stated. 
The nucleus of cells, the study of which began with the work of 
Brunton, Pldsz, and Miescher, has of recent years been very thoroughly 
worked at by Hoppe-Seyler, Kossel, and numerous other physiological 
chemists; the result will be gathered from the section in the preceding 
chapter on nuclein, and, as will be there seen, there are yet many gaps 
in our knowledge which require to be filled up. 
The proteids obtained from the cell protoplasm have been examined 
in simple cells such as those of lymphoid tissue, and in the more special- 
ised cells of secreting organs, such as the liver, kidneys, testis, and so forth. 
The main result is the same in all, though there are minor differences 
between individual cases. 
The proteid contained in greatest abundance is nucleo-proteid ; small 
quantities of globulin usually coagulating at the low temperature of 
50° C. or even lower, and minute traces of an albumin are also found. 
The nucleo-proteids from different cells differ in the amount of 
nuclein (as evidenced by the percentage of phosphorus) they contain. 3 
The nucleo-proteid from the thymus contains O'S per cent, of phosphorus. 
kidney 
liver ,, 
0-37 
1-45 
brain ,, 
0-5 
red marrow ,, 
1-6 
red corpuscles ,, 
0-68 
1-25 
Schmidt's fibrin ferment 
In my early work 4 on the proteids of cell protoplasm, I selected the 
cells of lymphatic glands, because one can obtain from these structures 
an abundant supply of comparatively simple cells ; later, I found that 
the cells of thymus 5 gave similar results. At first I described the pro- 
teids obtained as four in number, namely nucleo-proteid, cell globulin-a, 
cell globulin-jS, and cell albumin. The nucleo-proteid can be obtained 
either by Wooldridge's acetic acid method or by the sodium chloride 
process (p. 68). 
The material obtained by both methods is the same, though they 
differ in their physical condition ; that obtained by the sodium chloride 
process being more viscous than that by Wooldridge's method. That 
they are the same is shown by the facts that both give the same re- 
actions, which closely resemble those of globulins; both contain 
practically the same amount of phosphorus, and both produce intra- 
vascular coagulation. 6 
The term cell globulin was originally introduced by me as a con- 
venient designation for the proteids which are coagulable by heat in 
sodium sulphate extracts of the cells. The nucleo-proteid just men- 
tioned is viscid when extracted by sodium chloride and magnesium 
sulphate, but an extract with sodium sulphate solution does not exhibit 
1 "Studien ueber das Protoplasma," Berlin, 1881. 
- Untersuch. a. d. physiol. Inst. d. Univ. Heidelberg, 1882, Bd. ii. S. 273. 
3 Halliburton, Journ. Physiol., Cambridge and London. 1895, vol. xviii. p. 306. 
4 Proc. Roy. Soc. London, 1888, vol. xliv. p. 255; Jowrn. Physiol., Cambridge and 
London, 1888, vol. ix. p. 229. 5 Ibid., vol. xviii. p. 306. 
6 Halliburton and Brodie, ibid., 1894, vol. xvii. p. 135. 
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