24^ ESSAYS ANb OBSERVATIONS 



from what I obferved in the cafe of John 

 Parker, where we had examples of true 

 aneurifms in all their different ftages, I 

 think we have reafon to believe, that the 

 pulfation does not in general ceafe, (tho' 

 perhaps it may in fome rare cafes), till 

 the true coats of the artery have burfl. 

 For, in all the aneurifms where the coats 

 of the artery were intire, there was a 

 flrong pulfation to the laft, even in the 

 one of the left ham where there was a 

 large polypous concretion ; and, in the 

 one of the right ham, which at laft burft, 

 there v^as a ftrong pulfation long af- 

 ter the aneurifm had loft the appearance 

 and feel of a circumfcribed tumour, and 

 we had reafon to believe, that the true 

 coats of the artery had burft, and that i? 

 had degenerated into an aneurifm of the 

 mixed kind. Hence, furgeons ought 

 not too haftily to conclude, from the 

 want of pulfation, that foft tumours fir 

 tuated above large blood vefTels are not 

 aneurifms, but ought carefully to exa- 

 mine into their caufc, progrefs, fituation. 



