(611 ) 
Against the first of these possibilities HAMMARSTEN ') has raised 
serious objections, and by his later researches he came more and 
more to the conviction that fibringlobulin must be a somewhat 
changed soluble fibrin. 
A research of CALUGAREANU ?) was the occasion for experiments to 
be made in this direction. The author inter alia demonstrates that 
natriumfluoride, in strong concentration, greatly increases the effect 
quantities of fibrinferment. CALUGAREANU prepared horseoxalateplasma, 
which contained a quantity of fibrinferment so small, that the plasma 
remained fluid for a considerable time. 
If this plasma was mixed with natrium fluoride to a quantity of 
about 3°/,, either by addition of a saturated solution of NaFl or also 
of finely powdered NaFl, then there ensued an almost immediate 
coagulation. That the formed precipitate really is fibrin, CALCGAREANU 
derives from the fact, that it is like fibrin insoluble in diluted salt 
solutions. Further CanuGarranu discovered that horseoxalateplasma, 
if it was only perfectly free from ferment, did not coagulate by 
addition even of several volumina 3°/, Na Fl. When therefore no. 
ferment is present the natriumfluoride remains inactive, from which 
CALCGAREANV concludes that the Na Fl exercises its influence on the 
fibrinferment but not on the fibrinogen. 
When the experiments of CALUGAREANU were repeated I obtained 
results which partly differed from his. 
It namely appeared that perfectly fermentfree solutions containing 
fibrinogen gave a precipitate with natriumfluoride; this precipitate 
is in case horsefibrinogen is used gelatinous and in consequence 
reminds one more or less of coagulation; if however oxenfibrinogen 
or oxenbloodplasma is used, the precipitate is flocculent and does 
therefore not, outwardly at least, resemble coagulation. 
In the second place it appeared that the precipitate formed by 
NaFl could be easily dissolved, when treated properly, and that 
these solutions coagulated with fibrinferment. 
Some experements I will describe here in detail. 
A rabbit was injected in the vena jugularis with 65 eem. leech- 
extract, next the blood out of the Carotis was received in a centri- 
fugalglass covered with paraffine and the corpuscles where centri- 
fugalised off. Plasma in this way prepared contains no ferment as 
PEKELHARING *) has demonstrated; the plasma, meant here, remained 
1) Pflügers Archiv., Bd. 22, p. 431. 
*) Arch. internat. de Physiol. Vol. IL, p. 12. 
5) Untersuchungen über das Fibrinferment. Verhand. Kon. Akad. van Wet. 
Amsterdam 1892, 
42 
Proceedings Royal Acad. Amsterdam. Vol. VIL 
