TRANSACTIONS OF THE SECTIONS. 675 



the commencement of the mflammation, in the five cases of 

 Avhich an account was read. The extent of the inflammation 

 was various. In all the cases, the- artery leading to the in- 

 flamed part, when laid bare as high as the groin as soon as 

 possible after the death of the animal, was larger in its whole 

 length, i. e. had contracted less at the moment of death, than 

 that of the sound limb. In two of the cases, where the inflam- 

 mation was of long standing, and the coats of the artery ap- 

 peared to have been affected by it, this vessel at the second ex- 

 amination appeared smaller than the artery of the sound limb, 

 having not only contracted less at the moment of death, but di- 

 lated less after death, than the artery in the natural state. In 

 the other cases the artery of the inflamed limb remained larger 

 than the other at the second examination ; and it vi^as further 

 obvious that its elasticity was impaired, for when slit open and 

 smoothed out, it had less power than the sound artery of reco- 

 vering the cylindrical form. 



In all the cases, the artery of the inflamed limb retained after 

 death a considerable quantity of blood, while the other was al- 

 most empty; and that this was not owing to inflammatory 

 effusion, preventing the artery of the affected limb from empty- 

 ing itself at the time of death, was proved, in two of the cases, 

 by cutting across the vessel, immediately on the death of the 

 animal, a little above the inflamed part, whereby it had full op- 

 portunity to rid itself of its blood, if it had retained the power 

 to do so. 



One of these observations was made in the presence of Dr. 

 Yelloly, Dr. Clark, Dr. Fletcher, Mr. Broughton, Mr. Clift, 

 and Mr. Bracy Clark ; and it may be added here, that in a sub- 

 sequent experiment, in which Dr. Alison and Mr. Dick were 

 assisted by Dr. Fletcher, they obtained further proof of the loss 

 of elasticity in the artery of an inflamed limb, by finding that 

 after it had been distended by a given weight of mercury (in 

 the way practised by Poiseville,) it had less power than the 

 corresponding sound artery, to contract on itself and expel its 

 contents when the distending force was withdrawn. But this 

 last experiment was made too long after the death of the ani- 

 mal to justify an inference as to the strictly vital power of the 

 vessel. 



Dr. Alison stated, that it seems now generally admitted by mi- 

 croscopical observers, that during by far the greatest part, and 

 during the highest intensity of inflammation, nothing but dila- 

 tation or relaxation of the small vessels of the inflamed part can 

 be perceived. If the present observations shall be confirmed 

 by others, they will show more distinctly than any statements 



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