he
annoyance of fleas and pediculi. Drinking water may be purified by
aeration, or by straining, boiling and subsequent sedimentation and
removal of the sediment by filtration through fresh and clean sand.
For the wealthy, the water may be distilled in an alembic, if such an
apparatus is obtainable. Avicenna says that bad water may be corrected
by the addition of vinegar. Exposure to the midday sun and to the
nocturnal cold, constipation and diarrhoea should be avoided, and
prompt attention should be given to all disorders of the health.

To these wise counsels Gilbert courteously adds a medieval _bon
voyage_ in these words:

"_Dominus autem omnia dirigat in tranquilitate. Amen._"

It has been already remarked upon a preceding page that Gilbert of
England was not a surgeon. Nevertheless it is only fair to say that
the surgical chapters of the Compendium present a more scientific and
complete view of surgical art, as then known, than any contemporaneous
writings of the Christian West, outside of Italy.

It is well known that during the Middle Ages the practice of surgery
in western Europe was generally regarded as disreputable, and
operative surgery was for the most part relegated to butchers,
barbers, bath-keepers, executioners, itinerant herniotomists and
oculists, _et id omne genus_, whose pernicious activity continued to
make life precarious far down into the modern period.

In Italy alone did surgery vindicate for itself an equality with
medicine, and the pioneer of this advance was Roger of Parma, who, as
we have seen, flourished early in the thirteenth century. Roger and
his pupil Roland, with the somewhat mythical "Four Masters" (_Quatuor
Magistri_), were the surgical representatives of the School of
Salernum, while Hugo (Borgognoni) di Lucca and his more famous son
Theodorius represented the rival school of Bologna. Equally famous
Italian surgeons of this century were Bruno of Logoburgo (in Calabria)
and Gulielmus of Saliceto (1275), the master of Lanfranchi (1296).
Gilbert of England, as a pupil of Salernum, naturally followed the
surgical teachings of that school, and we have already noticed that
his chapters on surgery are taken chiefly from the writings of Roger
of Parma, though the name of neither Roger, nor indeed of any other
distinctly surgical writer, is mentioned in the Compendium. How
closely in some cases Gilbert followed his masters may best be seen
by a comparison of their respective chapters