7 'HE OKIES OF CO A G ULA TION. 1 7 5 
administered nucleo-proteids or snake venom lie employed, then these 
additions do not produce coagulation. 1 In view of the fact that 
calcium chloride will nut, under these circumstances, produce coagula- 
tion, the hypothesis of Freund and Pekelharing, that "peptones" 
deprive blood of its coagulability by combining with its calcium salts, 
loses probability. 
Peptone injected intravenously rapidly disappears from the blood.- The 
action of peptone differs from that of leech extract, in that a second dose, 
given soon after the action of the first dose has passed off, fails to produce an 
effect on coagulability. .Moreover, the blood of a "peptonised" dog confers 
immunity from the action of peptone, if injected intravenously into a second 
animal. 3 
The properties of peptone plasma, and the effects of leucocytes and 
their saline extracts upon the coagulability of blood, were carefully 
studied by Wboldridge. This observer found, as already stated, that if 
peptone plasma be kept for a time at 0° a precipitate forms, which takes 
the form, under the microscope, of minute discoid particles, almost exactly 
similar to blood platelets. The substance thus precipitated was termed 
" A-fibrinogen " by Wooldridge, while he named the substance precipit- 
able by half-saturation with NaCl " B-fibrinogen " ; this is the same 
thing as fibrinogen as ordinarily understood. After the removal of the 
A-fibrinogen, the coagulability of peptone plasma by CO, and other 
conditions is greatly diminished or altogether lost, but is restored on 
dissolving the A-fibrinogen again with the aid of warmth. 
"Wooldridge's A-fibrinogen is also obtainable, as Wright has shown, by 
cooling oxalate plasma, and it is probably composed mainly, if not entirely, 
of nucleo-proteid. It has been shown by Hammarsten that if by prolonged 
cooling and filtration it is removed as much as possible from oxalated plasma, 
the plasma will not coagulate on the addition of sufficient lime salts to more 
than balance the excess of oxalic acid, hut that, if the precipitate be collected 
and treated with lime salts, it furnishes, on subsequently removing the 
lime by oxalate, a powerful thrombin or fibrin ferment. Hammarsten 
accordingly terms the substance in question, which is precipitated by cold 
from plasma, prothrombin, and considers that it can only be converted into 
thrombin by the action upon it of lime salts. Pekelharing regards the 
precipitate in question as composed of nucleo-proteid, and considers that the 
lime acts by combining with it to form fibrin ferment. 
The addition of lymph cells (washed with 0-6 per cent. JSTaCl solution) 
to peptone plasma causes its coagulation outside the body, and also acceler- 
ates the coagulation of ordinary blood in vitro, whereas the intravenous 
injection of salt solution holding these washed lymph cells in suspension 
produces an incoagulable condition (negative phase) of blood, which 
does not then coagulate, even on withdrawal. But on addition of some 
of this fluid, holding cells in suspension, to such blood after withdrawal, 
coagulation is rapidly produced. The loss of coagulability of peptone 
plasma is not due, as was supposed by A. Schmidt, to the disappearance 
and disintegration of leucocytes, for, as Wooldridge showed, the addition 
1 C. J. Martin, op. cit., pp. 35-40. According to Dastre and Floresco, the chief cause of 
the lack of coagulation in peptone plasma is its high alkalinity {Arch, dephysiol. norm, et 
path., Paris, 1897, p. -216). 
2 Schmidt-Mulheim, loc. cit. 
3 Contejean, Arch, dephysiol. norm, etpath., Paris, lS9. r >. 
