44^ ESSAYS AND OBSERVATION^ 



plaining of a flrong pulfation in thd 

 part, may lead us to fufpedt what the 

 cafe is, though we can never be certain 

 till it can be felt or feen. But, when aneu- 

 rifms are fituated in the neck, or in the 

 extremities, then they are immediately 

 diflinguiflied by their yielding to the 

 fingers, and having a flrong pulfation, 

 though afterwards, when they grow large, 

 they fomecimes lofe it. 



Most aneurifms gradually increafein 

 their fize, and, fooner or later, they pro- 

 trude towards that fide where they meet 

 with the lead refiflance *, as we fee by 



the 



* De Haen gives an inftance of an aneurlfm of the 

 aorta, which protruded between the fecond and third 

 ribs of the left fide, where the external tumour, inftead 

 of increafing as generally happens, fuddenly difappear- 

 ed, and was not to be perceived for above a month be- 

 fore the patient's death, though, upon difledlion; the a- 

 orta at its curvature was found to be dilated to the fize 

 of three fifts : Ce Haen attributes this fudden difap- 

 pearance of the external humour to the weight of th6 

 aneurifmal fac having loofened its attachment, and to 

 its having fallen more within the thorax when the pa-^ 

 licnt lay on the right fide, for the difficulty of breath- 

 ing, and other fymptoms of opprefTid lungs, increafei 

 immediately on its difappeArance. Ratio Medsnd. p ir< 

 4. cap. 2. 17 9. 



