( 613 ) 
serum, the coagulation begins (at 37°) after ten minutes; after an 
hour a solid clot was formed. 
Placed at 37° a tube with 5 eem. of the same solution, without 
ferment for control, remained perfectly fluid. 
The above mentioned experiments were now repeated with horse- 
oxalateplasma, which was not perfectly free from ferment, as was 
obvious from the partial clotting of the received blood; the results 
were in general the same; the precipitate obtained with Na Fl dis- 
solved only with somewhat more difficulty; the solution of this 
precipitate meanwhile possessed the properties of a tibrinogen solution 
and coagulated with fibrinferment. 
Further experiments were taken with fermentfree oxenfibrinogen 
prepared after the method of HaAMMARSTEN. It was stated that to 
precipitate this fibrinogen with NaF] more natrium fluoride solution 
was needed than for horsefibrinogen. The flocculent precipitate obtained 
with NaFl dissolved at 37° more easily in a diluted salt solution 
than the horsefibrinogen precipitated with NaFl; on the contrary less 
easily in */,,"/, ammonia; rather great quantities dissolved already at the 
temperature of the room in 8—5°/, NaCl. The coagulation temperature 
of the neutral solution, containing about 3°/, salt was at 53—54°. 
addition of acetic acid caused a precipitate which dissolved in excess ; 
by half saturating with NaCl the fibrinogen could be precipitated. 
That the solution coagulates with fibrinferment appears from the 
following experiment. 
5 eem. of the solution in 3°/, NaCl + 5 drops of oxenbloodserum. 
Complete clotting after two hours. 
Although it might seem after the above mentioned experiments 
that the fibrinogen remains unaltered on being precipitated with 
Na Fl, a closer inquiry brings to light a remarkable alteration. If 
namely a solution of fibrinogen precipitated with Na Fl is heated to 
55—58", very little fibringlobulin is found in the liquid filtered off 
from the coagulum; if the fibrinogen is precipitated twice with 
vatrium fluoride, no or only few traces of fibringlobulin can be 
obtained from the solution as appears from the following experiments. 
I. A solution of fibrinogen prepared after the method of Ham- 
MARSTEN was partly precipitated twice with Na Fl; the last precipitate 
was dissolved in */,,°/, ammonia and the solution was neutralised 
after addition of salt; 8 eem. of this solution, which contained 
0.445°/, fibrinogen were heated for five minutes to 55—60°, then 
it was filtered; the clear filtrate was heated to 72°, by which only 
a small opalescence ensued, which did not increase perceptibly after 
the liquid had been made slightly acid and afterwards boiled. 
