s is
comparatively a modern idea, and that most of the principles of
conservation of human tissues and the prevention of deterioration and
disease are distinctly modern. It needs only a little consideration of
Arculanus' instruction in the matter of the teeth, however, to undo any
such false impression. For obvious reasons I prefer to quote Guerini's
summation of this medieval student of dentistry's rules for dental
hygiene:

"For the preservation of teeth--considered by him, quite
rightly, a matter of great importance--Giovanni of Arcoli
repeats the various counsels given on the subject by preceding
writers, but he gives them as ten distinct canons or rules,
creating in this way a kind of decalogue of dental hygiene.
These rules are: (1) It is necessary to guard against the
corruption of food and drink within the stomach; therefore,
easily corruptible food--milk, salt fish, etc.--must not be
partaken of, and after meals all excessive movement, running
exercises, bathing, coitus, and other causes that impair the
digestion, must also be avoided. (2) Everything must be
avoided that may provoke vomiting. (3) Sweet and viscous
food--such as dried figs, preserves made with honey,
etc.--must not be partaken of. (4) Hard things must not be
broken with the teeth. (5) All food, drink, and other
substances that set the teeth on edge must be avoided. (6)
Food that is too hot or too cold must be avoided, and
especially the rapid succession of hot and cold, and vice
versa. (7) Leeks must not be eaten, as such a food, by its own
nature, is injurious to the teeth. (8) The teeth must be
cleaned at once, after every meal, from the particles of food
left in them; and for this purpose thin pieces of wood should
be used, somewhat broad at the ends, but not sharp-pointed or
edged; and preference should be given to small cypress twigs,
to the wood of aloes, or pine, rosemary, or juniper and
similar sorts of wood which are rather bitter and styptic;
care must, however, be taken not to search too long in the
dental interstices and not to injure the gums or shake the
teeth. (9) After this it is necessary to rinse the mouth by
using by preference a vinous decoction of sage, or one of
cinnamon, mastich, gallia, moschata, cubeb, juniper seeds,
root of cyperus, and rosemary leaves. (10) T