ed by such pressure into the skull. They were particularly
anxious to detect linear fractures. One of their methods of negative
diagnosis for fractures of the skull was that if the patient were able
to bring his teeth together strongly, or to crack a nut without pain,
then there was no fracture present. One of the commentators, however,
adds to this "_sed hoc aliquando fallit_--but this sign sometimes
fails." Split or crack fractures were also diagnosticated by the method
suggested by Hippocrates of pouring some colored fluid over the skull
after the bone was exposed, when the linear fracture would show by
coloration. The Four Masters suggest a sort of red ink for this purpose.

While they have so much to say about fractures of the skull and insist,
over and over again, that though all depressed fractures need treatment
and many fissure fractures require trepanation, still great care must be
exercised in the selection of cases. They say, for instance, that
surgeons who in every serious wound of the head have recourse to the
trephine must be looked upon as "fools and idiots" (_idioti et
stolidi_). In the light of what we now know about the necessity for
absolute cleanliness,--asepsis as we have come to call it,--it is rather
startling to note the directions that are given to a surgeon to be
observed on the day when he is to do a trepanation. For obvious reasons
I prefer to quote it in the Latin: "_Et nota quod die ilia cavendum est
medico a coitu et malis cibis aera corrumpentibus, ut sunt allia, cepe,
et hujusmodi, et colloquio mulieris menstruosae, et manus ejus debent
esse mundae, etc._" My quotation is from Gurlt, Vol. I, p. 707. The
directions are most interesting. The surgeon's hands must be clean, he
must avoid the taking of food that may corrupt the air, such as onions,
leeks, and the like; must avoid menstruating and other women, and in
general must keep himself in a state of absolute cleanliness.

To read a passage like this separated from its context and without
knowing anything about the wonderful powers of observation of the men
from whom it comes, it would be very easy to think that it is merely a
set of general directions which they had made on some general principle,
perhaps quite foolish in itself. We know, however, that these men had by
observation detected nearly every feature of importance in fractures of
the skull, their indications and contra-indications for operation and
their prognosis. They had a