wasps, bees, ants and spiders.

Space does not permit a careful review of this interesting subject,
but a novel form of poisoning by the use of quicksilver is startling
enough to claim our attention. Gilbert tells us that pouring metallic
mercury into the ear produces the most distressing symptoms, severe
pain, delirium, convulsions, epilepsy, apoplexy and, if the metal
penetrates to the brain, ultimate death. In the treatment of this
condition certain physicians had recommended the insertion into the
ear of a thin lamina of lead, upon which it was believed that the
mercury would fasten itself and might thus be drawn out. Avicenna
objected to this that the mercury was liable to speedily pass into the
ear so deeply as to be beyond the reach of the lead. Gilbert suggests
as an improvement of the treatment that a thin lamina of gold be
substituted for the lead, "because mercury thirsts after gold as
animals do after water, as it is held in the books on alchemy" (_in
libris allzinimicis_). This fact, too, he tells us can be easily
demonstrated externally by placing upon a plate a portion of gold,
and near, but not in contact with it, a little quicksilver, when the
silver, he says, will at once "leap" upon the gold. Avicenna suggests
that the patient stand upon the foot of the side affected, lean his
head over to the same side, steady it in that position with the hands,
and then leap suddenly over upon the other foot--demonstrating thereby
his knowledge of both gravity and inertia. Manifestly our "laboratory
physicians" of the present day can assume no airs of priority!

The Compendium closes with two very sensible chapters on the hygiene
of travel, entitled "_De regimine iter agentium_" and "_De regimine
transfretantium_."