THEIR AMOUNT OF FIBRIN. 313 



place ; and sometimes we may observe the formation of a coagulum 

 in these fluids after they have stood from 10 to 24 hours (Schwann 

 and Magnus,* Delaharpe,f Scherer,{ Quevenne). Moreover, 

 this fibrin does not differ chemically from blood-fibrin ; we know 

 also that a " fibrin of slow coagulation" may occur in the blood, of 

 which Polli || has given numerous examples. We certainly cannot 

 always state with accuracy in individual cases what it is that 

 impedes the coagulation, but the causes are generally much the 

 same, namely, moderate attenuation with water, an excess of 

 alkaline salts, abundance of carbonic acid, &c,, which, as we have 

 already seen in p. 196, more or less impede the separation of the 

 fibrin. Moreover, the chemical reactions presented by this fibrin 

 are precisely the same as those of ordinary fibrin. 



If we should suppose that the question, whether or not the 

 fibrin in these pathological effusions is of a different kind, could be 

 decided by elementary analyses, we should be very far from the 

 truth ; for, as in all experiments of this nature, we should find 

 differences enough, but they would depend upon the impossibility 

 of our obtaining such substances as fibrin in a state of chemical 

 purity, and fit for an elementary analysis ; we need not here repeat 

 what has been already stated (in vol. i., p. 352) respecting the 

 unfitness of fibrin for ultimate analysis, and (in vol. i., pp. 29-31) 

 regarding the general cautions requisite in such cases. 



With regard to the quantity of fibrin which we find in 

 transudations, it is obvious, from what has been already stated, 

 that it presents very great differences, although it is always some- 

 what less than that of the corresponding blood-plasma. This 

 obviously only holds good with regard to fresh transudations ; for 

 when they have existed for some time in the living body, they may 

 on the one hand be found to have been deprived of a great part of 

 their water, or the fibrinous coagulum may have already passed 

 into a state of cell-formation an object to which other substances 

 in the transudation, besides the fibrin, may be applied ; in these 

 cases we certainly meet with far more fibrin in the transudation 

 than in the liquor sanguinis, if we calculate as fibrin all un dis- 

 solved or insoluble matters. 



No fibrin can be detected in those normal transudations which 



* Muller's Arch. 1838, S. 95. 



t Arch. ge'n. de Med. Juin, 1 842. 



J Untersuch. z. Pathol. S. 106 u. 110. 



Jouro. de Pharm. Nov. 1837. 



I! Eckstein's Handbibl. des Ausl. Heft. 4, S. 2532.. 



