(seq. 191)

91

Lect. 7.

& therefore preserves the Fibres of the Muscles
from being abraded by the Bones. It is of great Use as
to the Blood Vessels, whose capillary Extremities enter
the Bones, & might be easily cut in two, if it was not
for this Membrane, & so the Body of the Bone Would be
deformed of its Nourishment. Great Care is requisite in
Fractures - & great Danger is sometimes to be apprehend=
ed for the Periostium being firm often does much misch=
ief by confining Corrupted Matter between it & y^e Bone
& bringing on a Caries of the latter, which Matter, if it
could be discovered soon enough; might be dislodged by
an Incision & bad Consequences prevented - The Bones
often become caries in the Lues Venerea - The Perios=
teum has many Nerves, but not very sensible, unless
disc[?] - Of Cartilages. A Cartilage is a smooth
solid gristly & elastic Substance, softer than a Bone, &
harder than a Ligament - They serve 3 Purposes, 1^st to
prevent the Bones abrading each other, as the Patella in
y^e Joint of y^e Knee, or as in the Os Femoris, & Tibia, where
the Cartilages are nearly annular, & serve as a loose Ring
between the Parts of Hookhinges of heavy Gates - 2^d. They
give Shape to the Parts, as those of the outer Ear & Nose