ANATOMY. 
tant and tender organs from external inju- 
ries, there must be some firm prop-work in- 
terwoven through the whole. And, in fact, 
for such purposes the bones are given. 
The prop-work must not be made into 
one rigid fabric, for that would prevent mo- 
tion. Therefore there are a number of 
bones. These pieces must all be firmly 
bound together to prevent their dislocation, 
and this end is perfectly well answered by 
the ligaments. The extremities of these 
bony pieces, where they move and rub upon 
one another, must have smooth and slippery 
surfaces, for easy motion. This is most 
happily provided for by the cartilages and 
mucus of the joints. 
The interstices of all these parts must be 
filled up with some soft and ductile matter, 
which shall keep them in their places, unite 
them, and at the same time allow them to 
move a little upon one another. This end 
is accordingly answered by the cellular 
membrane, or adipous substance. 
There must be an outward covering over 
the whole apparatus, both to give it a firm 
compactness, and to defend it from a thou- 
sand injuries, which, in fact, are the very 
purposes of the skin, and other integu- 
ments. 
As she is made for society and inter- 
course with beings of her own kind, she 
must be endued with powers of expressing 
and communicating her thoughts by some 
sensible marks or signs, which shall be both 
easy to herself, and admit of great variety. 
Hence she is provided with the organs and 
faculty of speech, by which she can throw 
out signs with amazing facility, and vary 
them without end. 
Thus we have built up an animal body 
which would seem to be pretty complete ; 
but we have not yet made any provision for 
its duration : and, as it is the nature of mat- 
ter to be altered and worked upon by mat- 
ter, so in a very little time such a living 
creature must be destroyed, if there is no 
provision for repairing the injuries which she 
must commit upon herself, and the injuries 
which she must be exposed to from without. 
Therefore a treasure of blood is actually 
provided in the heart and vascular system, 
full of nutritious and healing particles, fluid 
enough to penetrate into the minutest parts 
of the animal. Impelled by the heart, and 
conveyed by the arteries, it washes every 
part, builds up what was broken down, and 
sweeps away the old and useless materials. 
Hence we see the necessity or advantage 
of the heart and arterial system : the over- 
plus of this blood, beyond what was required 
to repair the present damages of the ma- 
chine, must not be lost, but should be re- 
turned again to the heart; and for this pur- 
pose the venal system is actually provided. 
These requisites in the animal explain, a 
priori, the circulation of the blood. 
The old materials, which are become use- 
less, and are swept off by the current of 
blood, must be separated and thrown out of 
the system. Therefore glands, the organs 
of secretion, are given, for straining what- 
ever is redundant, vapid, or noxious, from 
the mass of blood; and when strained, it i* 
thrown out by excretories. 
Now, as the fabric must be constantly 
wearing, the reparation must be carried on 
without intermission, and the strainers must 
always be employed : therefore there is ac- 
tually a perpetual circulation of the blood, 
and the secretions are always going on. 
But even all this provision would not be 
sufficient; for that store of blood would 
soon be consumed, and the fabric would 
break down, if there were not a provision 
made for fresh supplies. These we observe, 
in fact, are profusely scattered round her in 
the animal and vegetable kingdoms; and 
she is provided with hands, the finest in- 
struments that could have been contrived, 
for gathering them, and for preparing them 
in a variety of different ways for the mouth. 
These supplies, which we call food, must be 
considerably changed; they must be con- 
verted into blood : therefore she is provided 
with teeth for cutting atid bruising the food, 
and with a stomach for melting it down; in 
short, with all the organs subservient to 
digestion. The finer parts of the aliments 
only can be usefal in the constitution: these 
must be taken up, and conveyed into the 
blood, and the dregs must be thrown off. 
With this view the intestinal canal is con- 
structed. It separates the nutritious part, 
which we call chyle, to be conveyed into 
the blood by the system of absorbent ves- 
sels ; and the feces pass downwards, to be 
conducted out of the body. 
Now we have got our animal, not only 
furnished with what is wanted for its imme- 
diate existence, but also with the power of 
spinning out that existence to an indefinite 
length of time. But its duration, we may 
presume, must necessarily be limited: for 
as it is nourished, grows, and is raised up to 
its full strength and perfection, so it must, in 
time, in common with all material things, 
begin to decay, and then hurry on to final 
ruin. Hence we see the necessity of a 
