On the origin of the fibrin ferment / by L.C. Wooldridge ; communicated by M. Foster.

  • Wooldridge, Leonard Charles, 1857-1889.
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: On the origin of the fibrin ferment / by L.C. Wooldridge ; communicated by M. Foster. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    I. A measured quantity of blood was received directly from the carotid of a dog into a vessel containing an equal bulk of a 10 per cent, solution of common salt, great care being taken that the com- plete admixture of the blood and salt solution was effected as rapidly as possible. By the help of the centrifugal machine plasma was sepa- rated from this salted blood, and this plasma was again subjected to the action of the machine until all traces of formed elements were removed. As is well known, a portion of such a plasma diluted with five times its bulk of water coagulates rapidly, whereas the undiluted plasma remains liquid for an almost indefinite time. According to commonly received opinions, such a salted plasma contains all the fibrin factors, including the ferment, the latter having already passed out of the cells into the plasma : and the reason given of the absence of coagulation in such a salted plasma and its occurrence upon dilution is, that the presence of the salts presents a hindrance to the action of the fibrin ferment, and that this obstructive influence of the salt is removed by the dilution of the mass. No one, however, as far as I know, has taken the trouble to ascer- tain whether fibrin ferment is present in such salted plasma. And, as a matter of fact, it is not; whereas it does make its appearance as soon as dilution with water has taken place, as the following experi- ment shows :— A portion of the undiluted salted plasma was treated with absolute alcohol in large excess, and the precipitate after being allowed to remain under the alcohol for three or four weeks was dried at a low iemperature and extracted with water^—that is to say, the plasma was treated in the way usually adopted for obtaining a solution of ferment fairly free from proteids, &c. A portion of the diluted plasma, or rather of the serum resulting from the coagulation of the diluted plasma, was treated in an exactly similar manner. The aqueous extract of the diluted plasma brought about coagula- tion in specimens of magnesium sulphate plas>ma (such as is usually employed for testing the presence of fibrin ferment) in from ten to fifteen minutes. The aqueous extract of the undiluted plasma brought about no coagulation in specimens of the same magnesium sulphate plasma, even after the lapse of eighteen hours. The conditions of each experiment were made as exactly alike as possible; and the conclusion seemed inevitable that ferment is present in the diluted and coagulated plasma, but absent from the undiluted plasma. This conclusion is, moreover, supported by the following experi- ments:—To a portion of the undiluted plasma above mentioned a small quantity of fibrin ferment was added, in the form of the dried precipitate thrown down by alcohol, i.e., a mixture of coagulated proteids and ferment. Coagulation took place. I have no record of