PHYSICAL AND LITERARY. 489 



ly fliut up, by inflammation, or tumor 

 of any kind, fo as to caufe a retention 

 of urine. The wliolc fubflance of it 

 will be increafed, partly from the fpread- 

 ing of the obftrudion, but chiefly from 

 the diftenfion of its fides j by which all the 

 vefl!els are ftretched, ^nd enlarged every- 

 way, laterally as well as longitudinally 5 

 and now, rendered more capacious, a 

 greater quantity of fluids is fuffered to 

 flow into them. Hence it is that mem- 

 branes, kept conftantly in a ftate of di- 

 ftenfion, are obferved to grow thicker; 

 as appears in the uterus during gefl:a- 

 tion and incyfl:ed tumors ; in which 

 the inverting membrane, at firfl: of a de- 

 licate texture, in time becomes furprifing- 

 ly thick and ftrong. Guarinonius found 

 the bladder in thicknefs equal to the 

 middle finger of a man ; and in hiftiory 

 third, when moft inflamed, perhaps it 

 was mof'e *. 

 Vol. in. Q^qq It 



• A young gentleman informs me, that he faw a 

 Cafe in the Royal Infirmary at Edinburgh, accompa- 

 nied 



