The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million — John Stuart Mill — John Shaqi
The reason why : $b a careful collection of many hundreds of reasons for things which, though generally believed, are imperfectly understood. A book of condensed scientific knowledge for the million
John Stuart Mill · en
Cartilage 32·17 parts
Blood-vessels 1·13 "
Carbonate of lime 11·30 "
Phosphate of lime 51·04 "
Fluate of lime 2·00 "
Phosphate of Magnesia 1·16 "
Soda, chloride of sodium 1·20 "
------
100·00
925. _What are the uses of the bones?_
They _protect_ soft and delicate organs; they form a framework to which
the organs are attached, and by which they are _kept in their places_;
and they supply a _mechanism_, by which the _motions of the body are
produced_, in combination with the muscles.
926. _Why is the brain placed within the skull?_
Because that delicate and vital organ, being the _centre and the root
of the nervous system_, requires a position of the _greatest safety_.
927. _Why are the bones that constitute the vertebræ (back-bone)
hollowed out, so as to form a continuous groove?_
Because through that groove the _spinal cord_ passes out from the
brain. Being in the centre of that column of bones, the spinal cord
receives from them a similar protection _to that which the brain
obtains from the skull_.
928. _Why is the head set upon the neck?_
Because in that position it obtains the _freest motion_, can turn
in _any direction_, and is placed relatively to the other parts of
the body, in that situation where it acquires _the greatest possible
advantage_.
929. _Why are the eyes placed in the sockets of the skull?_
Because the bones of the skull _afford protection_ to the delicate and
complicated structure of the eyes, and supply points of attachment, and
grooves, by which the muscles are enabled to _turn the eyes freely_,
and thereby _extend the field of vision_.
[Verse: "Thus saith the Lord God unto these bones, Behold I will
cause breath to enter into you, and ye shall live:"]
930. _Why are the bones of the skull arched?_
Because in that form they acquire _greater strength_, and hence
the utmost degree of safety is combined with extreme _lightness of
material_.
[Illustration: Fig. 54.--VIEW OF THE BONES OF THE THORAX, OR CHEST,
SHOWING THE PROTECTION AFFORDED TO THE ORGANS OF CIRCULATION AND
RESPIRATION.]
A. The sternum, or breast-bone.
B B. The _ribs_, which rise a little from behind, and fall as they
come forward, by which they acquire a greater flexibility.
C C. The _cartilaginous points_ of the short ribs, by which their
expansive and compressive powers are much increased.
D E. Part of the vertebral column, or back-bone.
931. _Why are the bones of the skull divided by sutures (seams), with
points which fit into each other like small teeth?_
Because, by that arrangement, _concussions of the skull_, which might
be fatal to the brain, are _deadened_, and injuries from accident
_greatly modified_.