[ use J 
even the ufe of the trepan is now more indefinite than it 
was a century ago. The late Mr. Pott, as diligent and accu- 
-rate an obferver as any age or nation has produced, complains 
-“ of the darknefs and obfcurity of this part of furgery.” 
Enapiep by clofe and diligent obfervations, and by -exten- 
five practice in this line for above thirty years, I have ven- 
tured, under the aufpices of the Academy, to determine a quef 
tion, perhaps the niceft and moft involved in furgery. 
THE operation of the trepan is very ancient; but being 
confined to narrow limits, was feldom performed without the 
greateft caution and circum{fpection ; for it was interdicted over 
or near the futuras, near the os fquamofum, and or very near 
the occiput. This well explains an anecdote in our early hif- 
tory; for Connor Mac Neafla, king of Ulfter, that generous 
protector of the literati of his days, and contemporary with 
Julius Cefar, having his fkull fractured in battle, his firft 
furgeon, Finighin, refufed to apply the trepan till his fafety 
was guaranteed by the nobles of the country, in cafe it did 
not fucceed. 
But the experience of the laft and prefent centuries have 
proved, that there are very few parts of the head on which the 
trephine may not be applied when neceflary. However, this 
information, in itfelf fo interefting, has by no means anfwered 
the ends that fhould be expected from it ; for inftead of de- 
termining, or even attempting to limit the cafes to which it 
fhould 
