(612) 
fluid for a number of days, as long as it was kept, yet by addition 
of three times the volume of saturated natriumfluoridesolution a 
flocculent precipitate was slowly formed; a fibrinogensolution prepared 
from the plasma could also be precipitated by the addition of 
saturated natrium fluoride solution; by saturating with solid natrium 
fluoride a precipitate ensued immediately. 
Other experiments were taken with horsefibrinogen. The fibrinogen 
solutions used, which were prepared by three times precipitating 
with salt from oxalateplasma showed even after being preserved 
for several days, no trace of clotting; by addition of Ca Cl, no clotting 
was caused either at 37° or at the temperature of the room. In such 
a fibrinogen solution a thick precipitate is then immediately formed’) by 
addition of the double volume of saturated natrium fluoride solution ; 
this gelatinous precipitate can be easily wound round a glass rod and 
in this state be taken out of the liquid for further research. The 
precipitate washed by water showed the following properties. It did 
not dissolve perceptibly at the temperature of the room in 8——5°/, salt, 
„more easily the solving succeeded in this way, at the temperature 
of the body, or still better at 40—45°. On cooling, the precipitate 
does not return. The surest way to obtain a complete solution is to 
make use of */,,°/, ammonia as solvent; if the precipitate is divided 
with a glass rod, rather concentrated solutions can easily be prepared 
in this way. Such a solution can after addition of salt, to a quantity 
of 3 
when the concentration of the solution was very great, a part of the 
5°/, be neutralised without a precipitate forming anew (only 
dissolved substance precipitated often again after some time; this preci- 
pitate was solved however at 37°). Such a solution may be preci- 
pitated again in the same way, with the double volume saturated 
natrium fluoride solution and may be dissolved in */,,"/, ammonia. Such 
neutral solutions containing 3—5°/, salt and prepared by being once 
or twice precipitated with Na Fl possessed all the properties of fibri- 
nogen; by addition of an equal volume saturated salt solution, a 
ereat precipitate was formed; acetic acid caused a precipitate soluble 
in excess; the coagulation temperature was at 54°; the solutions 
coagulated quickly and completely with fibrinferment for which I 
mention the following experiments as example. 
5 eem. fibrinogen solution of 0.842°/,--1 cem. fibrinferment solution; 
the coagulation begins at 37° after half an hour; the tube further 
coagulates completely. 
5 ecm. of the same fibrinogen solution + 5 drops of oxenblood- 
1) The mixture contains then not much more than 3 0/, Na Fl. 
