204 BLOOD 



of inflammation, it was also termed the inflammatory crust. It 

 cannot be denied that the quantity of the fibrin exerts some influ- 

 ence on the thickness of the buffy coat, but it can never consti- 

 tute the sole cause; for we frequently observe inflammatory blood, 

 which is very rich in fibrin, form no crust, whilst, as we have 

 already noticed, blood that is poor in fibrin may in many chronic 

 affections present a crust of this nature. 



We have, therefore, to revert to many different proximate or 

 remote mechanical and chemical causes for an explanation of the 

 configuration of the clot in any special case. The observations 

 regarding the mechanical relations of the clot are only important 

 in a semeiotic point of view in special cases ; they are of no ser- 

 vice in the establishment of artificial families or groups of diseases. 



Before we pass to the further consideration of the substances 

 actually dissolved in the intercellular fluid, we have to notice some 

 bodies which remain suspended in the blood, or more correctly 

 speaking, in the serum, after the separation of the fibrin and the 

 blood-corpuscles. 



Hewson and Thomson are of opinion that they have found a 

 milky turbidity of the serum in blood taken some hours after a 

 meal ; but I have never observed anything of this kind either in 

 carnivorous or herbivorous animals, whose blood I have examined 

 at different periods after the administration of food. In a similar 

 manner the serum acquires, according to Hewson and Magendie, 

 a milky appearance after prolonged fasting. Nasse found that 

 the serum of the blood of pregnant women was in most cases 

 milky; very frequently, but not invariably, we observe that in 

 drunkards the serum presents an opalescent, almost milky tur- 

 bidity. This turbid appearance is generally due to the presence 

 of suspended fat, which may easily be detected by microscopical 

 examination or by shaking the serum with ether. 



Zimmermann has drawn attention to a kind of turbid serum, 

 which he has found in the blood in inflammatory conditions. This 

 turbidity depends upon the presence of very small dark particles, 

 or molecular granules ; and hence he was induced to assume the 

 existence of a special molecular fibrin, while Scherer, on the con- 

 trary, who has noticed similar instances of turbidity, inclines rather 

 to the opinion that these granules are separated albumen. My 

 own observations on the turbidity arising from molecular granules 

 lead me to concur in the latter view ; for I found that the turbidity 

 disappeared on the addition of neutral alkaline salts, when the serum 

 exhibited only a faint alkaline reaction; and hence we must 



