PHYSIOLOGICAL ACTION OF VENOM OF BLACK SNAKE. 179 
disappearance of spontaneous coagulability. Those samples in 
which clotting is delayed for a few hours, but which subsequently 
clot well, I shall refer to as ‘‘ weak negative phases,” while those 
in which spontaneous coagulation is entirely in abeyance, and 
which can only, be made to clot under a few special conditions, I 
shall designate “pronounced negative phases,” but it must be 
borne in mind that individual samples show every degree of loss 
of coagulability between these extremes. 
In plasmas which exhibit only a weak negative phase, clotting 
can be induced more or less readily by the addition of the following 
(1) Solution of nucleo-albumen (Wooldridge’s tissue-fibrinogen). 
(2) Calcium chloride. 
(3) Dilution. 
(4) Passage of CO, through the liquid. 
(5) Alexander Schmidt’s fibrin ferment. 
These are arranged in the order in which they are most active. 
As the negative phase becomes more and more pronounced, they 
lose their capacity to hasten or occasion clotting usually in the 
inverse order, although exceptions are not infrequent. Ina really 
| Pronounced negative phase, each and all of these additions are 
_ incapable of inducing coagulation. 
Such plasmas contain fibrinogen, for by heating, after previous 
< neutralisation, they yield a considerable precipitate at 55° C. The 
: fibrinogen would appear, however, to be present in a somewhat 
altered condition, for it is now no longer thrown out of solution 
by half saturation with NaCl. 
These plasmas although absolutely devoid of spontaneous 
Seagulability, can be made to yield fibrin, though the amount 
Fielded ®ppears to me to be very much less than that obtainable 
from an equal quantity of blood plasma, previous to the injection 
‘the Poison ; but as I have not made any quantitative determin- 
on of the amounts, Iam unable to speak with certainty on 
