ANATOMY. 
find their elasticity restores the body to its 
former state, when the compressing force 
ceases. 
In order still further to increase the 
strength of the compages, and to add a 
greater security against luxation, the verte- 
brse are articulated to each other by means 
of the processes before mentioned. And 
these processes so lock in with and over- 
wrap one another as to secure the body of 
the vertebra, not only from accidentally 
slipping, but even from being pushed out of 
its place by any violence short of that which 
would break the bone. The roots of the 
spinous processes are also joined to each 
other by very strong and highly elastic liga- 
mentous substances, which will tend power- 
fully to restore the column after it has been 
bent forwards. 
The general result is, that not only the 
motions of the human body necessary for 
the ordinary offices of life are performed 
with safety, but that it is an accident hardly 
ever heard of, that even the gesticulations 
of a harlequin distort his spine. 
The ribs are articulated by their posterior 
extremities to the bodies and to the trans- 
verse processes of the vertebra’, and the 
true ribs are also joined by means of their 
cartilages to the sternum. Two great ad- 
vantages are derived from the ribs having 
this cartilaginous portion. The effect of 
blows, or of any accidental violence, is 
eluded by the flexibility which they thus 
obtain ; and the elastic power of the carti- 
lages restores the ribs to their former posi- 
tion, after they have been raised by the in- 
tercostal muscles in breathing. 
Joints of the upper extremity . — The clavicle 
is articulated to the sternum at one end, and 
to the scapula at the other. 
The shoulder is formed by a round head 
of the humerus, which plays in a cup of the 
scapula ; and the ends of the bones are in- 
closed by a thick and strong ligamentous 
membrane, called the orbicular ligament. 
There is here, therefore, every latitude of 
motion allowed. 
In the elbow, on the contrary, the joint is 
a mere hinge : lateral motion is restrained 
by strong ligaments placed at the sides of 
the joint, and the fore-arm can therefore be 
moved only forwards and backwards. This 
joint is formed between the ulna and the 
humerus. 
The wrist is formed by the junction of 
the radius with the first phalanx of carpal 
bones. Its motion is very little more than 
that of a ginglymus. The Rotation of the 
hand and wrist, or what anatomists call the- 
pronation and supination, are performed by 
the radius revolving round the ulna, and car- 
rying the hand with it. In this case the 
elbow joint is fixed; neither does the joint 
of the wrist move ; but the radius moves 
freely round the ulna, and the hand is in- 
cluded in the motion. The pronation and 
supination of the hand are well exemplified 
in the use of the broad-sword, and in cud- 
gel-playing. 
The carpal and metacarpal bones are> 
united by joints and ligaments, but have no 
obvious motion on each other. The pha- 
langes of the fingers are also articulated by 
ginglymi, 
The bones of the pelvis are inseparably 
connected by adhering cartilaginous sur- 
faces and immense ligaments. Such is the 
strength of this union, that it will yield to 
no force but one that would destroy and, 
crush the whole fabric. 
Joints of the lower extremity . — In the hip, 
which supports the whole body, and which 
is the centre of motion of the whole in 
moving from place to place, we find an ap- 
paratus admitting of extensive motion, but 
at the same time most carefully guarded 
and strengthened. There is a very large 
rounded head of the thigh received into a 
deep cup of the os innominatum. Here it 
can revolve freely, and is prevented from 
escaping by thick and strong rising edges, 
that guard the brim of the cavity. From 
these edges there springs a very tough and 
stout orbicular ligament, which is firmly 
stretched over the head of the bone, and 
implanted into a contracted part called the 
neck. In order to provide still further for 
the security of so important a joint as the. 
hip, there is a short, strong ligament arising 
from the head of the ball, and implanted in 
the bottom of the cup. This affords a very 
great obstacle to any force tending to dis- 
place the bone; but at the same time lies in 
the bottom of the cavity, so as not to inter- 
fere with any of the ordinary motions. 
The knee-joint is formed by three bones : 
the head of the tibia, the condyles of the fe- 
mur, and the patella. It is a ginglymus, 
and its motions are accordingly restrained 
by two strong lateral ligaments, and it is 
secured still further by two immense liga- 
mentous ropes within the cavity of the 
joint, called the crucial ligaments. 
The ankle is a ginglymoid joint, formed 
by the tibia and fibula, together with the 
astragalus. This joint, which is an impor- 
tant one, as bearing the weight of the whol$ 
