UNDER THE SCULL. 



435 



is particularly interefling, when the effufion Is fituated 

 at the bottom of the fcuH. 



If inilead of trepanning twelve times, Mr. Marefchal 

 had feparated the dura mater from the cranium, following 

 the direclion of the fraclure, he would have certainly 

 reached the effufion, and the blood would have been eva- 

 cuated by the firft opening, although it muft have rifen 

 againft its own weight ; this will be eafily underftood by 

 phyfiologifts who advert to the force of prefliire the brain 

 exercifes on every part of the fcull, and compare it with 

 the refiftance the colledled blood may oppofe by its fpccific 

 weight. 



The danger arifmg from a feparation of the dura mater, 

 may perhaps be confulered as forbidding the method 1 re- 

 commend, but experience Ihevvs this feparation is not dan- 

 gerous, lince, as I have already faid, blood cannot colle£t 

 between thefe two parts, without feparation, and yet they re- 

 turn to their natural ftate, when the fluid is evacuated by 

 the trepan, even where the feparated parts have long re- 

 mained divided from each other by the interpolition of the 

 fluid. 



Of the cafes which fjpport my opinion, it will be fuffi'" 

 cient to mention the following. 



A young perfon after the fcarlet fever, had a violent 

 pain which fixed itfelf at the upper part of the head ; 

 every thing art could indicate was tried to efFedl a cure, 

 bleeding, bathing, cathartics, Internal remedies, topicals 

 of every kind, and bliftcrs on the affedted part, all had 

 failed : when I was confulted, I advifed the moxa, which 

 was applied to the difeafed part, and though a plentiful 

 fuppuration followed, the pain feemed to increafe, and 

 for fix months continued to augment; when I was again 

 requefted to give my advice. 1 prefcribed the trepan, 

 which operation was immediately performed, in the centre 

 of the painful part : the opening made in the fcull by this 

 2 L 3 means 



