CHAPTER III. 
to the tranfvcrfc proccflcs of the inferior vertebra, and againd the back- 
part of the body of the next fuperior; they alfo hinder them from diflo- 
cating to either fide; but the lad ribs are not fixed to the tranfverfe pre¬ 
cedes of the vertebras of the back, and therefore it is that luxations are 
moft frequently feen in this part; but the vertebrae of the loins arc receiv¬ 
ed into deep cavities, and are tyed with much flrongcr ligaments for their 
fccurity. Each joint of the vertebrae, except the two uppermod, has two 
centers of motion, one upon the bodies of the vertebras, when the trunk is 
bowed forwards; and the other at the articulations of the oblique pre¬ 
cedes, when the body is bowed backwards; from which dru (Share the ex- 
tenfors will have about twice the leaver to a£t with, and confequently 
twice the power to raife the trunk into an erect podure, that they have 
to carry it beyond that podure; for then the oblique precedes begin to 
be the centre of motion, and give a like advantage to the benders. With¬ 
out this contrivance it would be more difficult to keep the body ere£f, 
or to recover an erc6f podure with confiderable drength after a bend of 
the body. 
The ribs (Tab. xiv. xv.) are twelve in number on each fide; the feven 
uppermod are called true ribs, becaufe their cartilages reach thedernum; 
and the five lowed are called badard-ribs. They are articulated to the bo¬ 
dies of the twelve vertebra: of the back, and all, except the two or three 
lad, are articulated to their tranfverfe procedes, and the under fide of the 
middle ribs are hollowed for the pafiage of the intercodal vefiels. They 
defend the parts contained in the bread, and when they are drawn up¬ 
wards, the cavity of the bread is enlarged for infpiration, and fo the con¬ 
trary. In two children, which I have didefted, I found the ribs broke in¬ 
wards, and on the outfide a very plain print of a thumb and fingers, which 
had been done by their nurfes hoilfing them up on one hand, taking 
hold of their breads, and being often repeated, had broke the ribs in¬ 
wards like a green dick, without feparating the broken ends of them; 
I have alfo very frequently feen the diape of childrens breads quite ipoil- 
cd by dich tricks, which have occafioncd weaknefs of body, crooked- 
nefs, and other difeafes. 
Sternum, or bread-bone (Tab. xvi. xvii.) is generally made up of three 
fpongy bones, lometimes more; to this the true ribs are articulated by 
their cartilages, which fometimes in robud men have moveable joints, 
fuch as are feen in oxen and other quadrupeds. At the end of the der- 
num is the cartilago enfiformis, fo called from its drape, but it very often 
is double; there is alfo frequently found variety in the form of the car- 
