180 Cc. J. MARTIN. 
Plasmas which have lost all spontaneous coagulability m 
however be made to clot by the following means— 
(1) Addition of a saturated solution of NaCl up to an 
volume. 
(2) Addition of an equal volume of a saturated solution a 
MgSO, = é 
(3) Addition of acetic acid, until the plasma is just faintly acil 
(4) Similar addition of weak sulphuric, hydrochloric, or p 
phoric acids. (Oxalic acid is ineffectual). 
The addition of the saturated solutions of NaCl and MgS0. 
occasions a faint turbidity, and the plasma clots on standing# 
few minutes. The acids must be carefully added, just to acidif 
cation, when turbidity occurs. Until this point is reached, 
clotting ever occurs, and if too much be added, the fibrinogen s 
precipitated. This precipitate readily redissolves in excess of the 
acid, and when so redissolved I have never succeeded in producing 
coagulation. The fibrin formed under these circumstances has 
the appearance of ordinary fibrin. It is insoluble in weak sal” 
solutions, or dilute HCl (-2%), but swells up in the latter, 
digesting with pepsin it dissolves, leaving a perfectly clear sol 
Since the observations of Arthus and Pagés! the influenc? 
calcium in coagulation has been recognised to be of the ) 
importance. Blood, decalcified by drawing it into a solution 
soluble oxalate, or fluoride (Arthus and Pagés), has lost its cap® 
to clot, although this may be restored by the further addi 
calcium salt. The intravenous injection of sodium ° 
(Halliburton and Brodie),? or soap (Munk), also renders the 
incoagulable. Pekelharing® is of opinion that the din 
coagulability of blood after the intravenous injection of : 
and sometimes of nucleo-albumens is to be explained in the 
way. 
1 Archiv. de Physiol., Ser. v., T. 11., 1890, p. 739. 
2 Journal of Physiology, Vol. xvir., 1894. 
3 Centrbl. f. d. Med. Wiss., Bd. 45, 1892. 
