(Let | 
the unequivocal figns that matter is formed on the cerebrum, 
or on its covering; and in thefe cafes, however deplorable the 
event, there is no recourfe but in trepanning. It is a fad well 
known to perfons of extenfive practice, that though this mat- 
ter begins under the immediate point of percuffion, yet that it 
extends much further. To operate, then, to any effect, I would 
recommend the application of more than one crown of the 
trephine. For inftance, the firft perforation being made, I would 
immediately proceed to a fecond, including a fegment of the 
former circle in it, by which means the iffue of matter is more 
facilitated, and if it fhould be found neceflary to open the dura: 
mater, it will be done with the greater effect by extending the: 
wound of it. 
Concussions of the brain are generally fuppofed to require- 
the trepan. Dionis, an able writer of the laft century, judges 
that the lofs of fenfe and memory, immediately fucceeding a 
violent injury, are fufficient motives to proceed direéily to the 
operation, and he illuftrates his. pofition by a cafe in point *. 
Mr. Pott, though he very judicioufly points out what can 
be effected by the operation, namely, the raifing of depreffed 
bones, or the iffue of blood or matter, yet he becomes an advo- 
cate for it‘on ftupors immediately following a hurt. “ For though 
“* it may be refolved into fymptoms of concuffion,” fays he, “ yet 
'*extravafation may fo fpeedily follow the firft fhock as to carry 
“all the appearance of the firft, whilft the fecond’ is the real 
* caufe.” But 'to a certainty extravafations of blood, matter, of 
water (for I have met them all) do not immediately, nor for 
¥-3 fome: 
. 
* Cours D’Operations de Chirurgie, p. 510. 
f 
