TREATMENT OF INFLAMMATION. 167 



local disorder of the blood's motion similar to that 

 present in the incipient stage of inflammation (as 

 described by microscopical observers) is, in other 

 parts of the circulating system, productive of the 

 same changes in the physical composition of that 

 fluid as those now under consideration ; for we know 

 that in general the only condition required for the 

 production of a fibrinous coagulum within any blood- 

 vessel is a gradual and continued retardation of the 

 stream of blood. In the large concretions formed 

 in the heart and large vessels during a lingering 

 death we have one instance of the operation of this 

 law. But the successive fibrinous layers deposited 

 on the internal surface of an aneurisimal sac exhibit 

 a still closer resemblance to the phenomena presented 

 in an inflamed part, inasmuch as the globules there 

 manifest the same tendency to adhere to the walls 

 of the containing vessel. This adhesion of the 

 globules to the vascular walls seems to me to be 

 mainly referable to the well-known fact, that the 

 rate of motion of the external portion of a stream 

 traversing any tube is always less than that of the 

 central column : but it is by no means improbable 

 that, from their similarity in chemical composition 

 to the contiguous tissues, the so-called lymph glo- 

 bules may naturally possess a strong tendency to 

 adhere to them under certain favourable conditions. 

 Now, all observers agree that the flow of blood 

 through the vessels of an inflamed part is consider- 

 ably slower than natural ; we have, therefore, in this 

 case also, that local retardation of the stream of 

 blood which is recognised as capable of inducing 



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