THEIR CONSTITUENTS. 311 



of the organs cannot be readily isolated, and if we, consequently, 

 are unable to prove by a direct method that it contains fibrin, yet, 

 independently of the general belief, it is in the highest degree 

 probable that this nutrient fluid actually contains fibrin; for this 

 view is supported by the amount of fibrin occurring in lymph, by 

 the constitution of the nutrient fluid in the lower animals which 

 do not possess distinct blood-canals, and by the constant presence 

 of fibrin in the ordinary plastic exudations, as is very well seen in 

 the non-sanguineous secretion of fresh incised wounds a secretion 

 which has been accurately analysed by Schmidt.* 



Fibrin may very often be contained in the transudations, when, 

 from its small quantity, or from the metamorphoses which it has 

 already undergone, it may evade chemical detection. If we con- 

 sider that in the plasma of normal blood the quantity of fibrin is 

 only one-fortieth of that of the albumen, and if we suppose that 

 the diminution of the fibrin in the transudation only corresponds 

 to that of the albumen, there could never be more than a very 

 small, often almost inappreciable, quantity of fibrin in the effused 

 fluid ; if we further consider that the fibrin in the parenchymatous 

 juices is very often applied to the renovation or reparation of 

 tissues, and that in morbid transudations it soon commences to form 

 the groundwork of morphological structures, we need not wonder 

 that the fibrin is so often found to be absent. Most> however, 

 of the dropsical transudations which depend on too aqueous a con- 

 dition of the blood, or on a disturbance in the function of the 

 lymphatics, appear to be formed without any simultaneous sepa- 

 ration of fibrin ; at all events, the fact that too aqueous blood is 

 usually found to be a little richer in fibrin than normal blood, 

 seems to favour the view that in this case the fibrin is retained in 

 the circulating fluid. But however this may be, the fact elicited 

 by Vogel remains established, that fibrinous transudations are far 

 more frequent than is usually supposed to be the case, trusting to 

 ocular examination alone. 



The physical and chemical properties of the fibrin occurring in 

 transudations perfectly coincide in all essential points with those of 

 the blood-fibrin; the peculiarities which the transudation-fibrin 

 presents, are solely based on the physical and chemical relations 

 under which it is separated, as in the case of the fibrin of the 

 lymph and chyle, to which reference has already been made : the 

 chemist can lay down no such differences as "a fibrin infiltrated 

 with serum," a croupous or aphthous fibrin, or a pseudofibrin. 

 * Charakteristik d. Cholera, S. 134. 





