PARENCHYMATOUS AND SECRETORY INFLAMMATION". 435 



in a third part it can no longer be affirmed with cer- 

 tainty whether the one or the other is present. Here 

 therefore both substances appear as substitutes for one 

 another. Where the inflammatory irritation is more 

 violent, we see fibrine, where slight, mucus, appear. 



With regard to mucus, however, we know, that it 

 does not exist in the blood like fibrine. Although a 

 mucous membrane produces incredibly large masses of 

 mucus in a short time, they are nevertheless products 

 of the membrane itself ; the membrane is not infiltrated 

 with mucus coming from the blood, but the peculiar 

 niucin matter, the principle of mucus, is a product of 

 the membrane, and is conveyed to the surface by means 

 of the fluid oozing through (transuding) from the blood. 

 In the same manner I have also attempted, as I inti- 

 mated to you on a former occasion (p. 195), to over- 

 throw the opinion, which is wont to be entertained with 

 regard to the origin of fibrine. Whilst until now fibrine 

 has been regarded as a real transudation from the 

 liquor sanguinis, as the outflowing plasma, I have pro- 

 posed the explanation, that the fibrine, like the mucus, 

 is a local product of those tissues, on and in which it is 

 found, and that it is conveyed to the surface in the same 

 way as the mucus of the mucous membrane. I then 

 showed you, how we have in this way a most ready 

 explanation of the fact, that in proportion as, in a given 

 tissue, the production of fibrine increases, so also the 

 amount of fibrine in the blood increases ; and that the 

 fibrinous crasis is just as much a product of the local 

 disease, as the fibrinous exudation is a local product of 

 the local metamorphosis of matter. Never has any one 

 any more than it is possible for him by a change of 

 pressure directly to produce mucus from the blood in 

 any place which does not itself produce mucus been 

 able to produce fibrine by any change in the pressure of 



