ANATOMY. 
veins. These are found particularly in the 
extremities, and vary much in size at dif- 
ferent times. 
The vena cava superior is formed by three 
large trunks. 
1. Vena azygos, which returns the blood 
from the sides of the chest, and runs along 
the middle of the spine. 
2. Right subclavian, which is also made 
up by thre,e venous trunks, viz. the internal 
jugular, the external jugular, and the axil- 
lary. 
3. Left subclavian, formed in the same 
manner as the right. 
The external jugular vein returns the 
blood from the outside of the head, and runs 
along the neck, just under the skin. We 
sometimes bleed from this in affections of 
the head. 
The internal jugular is a very large vessel, 
lying deeper in the neck, and close to the 
carotid artery. It brings back the blood 
. from the brain. The danger in attempts at 
suicide consists -in dividing this vessel or 
the carotid artery, and not the external 
jugular vein. The axillary vein is made up 
of the vessels which bring the blood back 
from the arm. Besides the deep-seated veins, 
we have here a large superficial vessel, running 
along the outside of the fore-arm and arm, and 
called the cephalic vein ; another on the in- 
side, named the basilic. Between these in 
the fore-arm are found some veins called the 
median. At the bend of the elbow these 
last make up two large trunks, of which onb 
opens into the basilic, and the other into the 
cephalic vein. These are called vena nredia- 
na basilica, and vena mediana cephalica. It 
is in the, latter veins that we generally bleed 
when that operation is performed in the 
arm ; and as they run directly over the 
artery, the latter vessel is endangered by 
the lancet. 
The inferior vena eava is a very large 
trunk, running along the spine at the right 
side of the aorta. It returns the blood from 
all the lower parts of the body. It is made 
up by the junction of the two common iliac 
veins ; and as it ascends through the abdo- 
men, it receives the following venous trunks : 
the lumbar, spermatic, renal, and the im- 
mense vena; cavae hepaticae. 
The common iliac vein is formed by the 
junction of the external and internal iliacs. 
The latter brings back the blood from the 
cavity of the pelvis; the former returns it 
from the lower extremity. 
We have two large cutaneous veins to 
notice in the leg and thigh ; viz. the saphena 
major, which run/s up along the inner side 
both of the leg and thigh, and can be dis- 
tinctly seen in the living person when in the 
erect posture; the saphena minor, which 
runs over the calf of ,the leg. The former 
terminates in the femoral vein, near the 
abdomen, the latter in the popliteal vein. 
The vena portarum is a large vessel form- 
ed by the union of those veins which belong 
to the stomach and intestines, the spleen 
and pancreas. It conveys the blood, which 
has circulated through those organs, to the 
liver, and it branches out in that gland as 
arteries do in other parts. Its blood is re- 
turned from the liver by the hepatic veins, 
which have been already noticed. 
ORGANS OF ABSORPTION. 
The absorbents are a minute kind of ves- 
sels found in animal bodies, which attract 
and imbibe any fluid that is brought near 
their mouths. They are so minute and 
transparent, as not to be discovered in or- 
dinary dissection ; but by great labour they 
have at length been detected in great num- 
bers in every tribe of animals. As these 
vessels are transparent, their contents are 
visible, which circumstance occasioned them 
to receive the different denominations of 
lacteals and lymphatics. The former were 
so called, because they imbibed the 
chyle, a milky fluid, from the bowels ; 
whilst the latter, containing much lymph, 
which they had taken up from all the inter- 
stices of the body, were therefore named 
lymphatics. The discovery of this system 
of vessels is referred to the seventeenth 
century. But at first their number did not 
appear sufficient to perform the whole 
function of absorption; neither had they 
been discovered in birds or fishes, whence 
anatomists still retained the idea that the 
veins participated in this important office. 
The merit of first demonstrating the ab- 
sorbing vessels in those animals belongs to 
Mr. Hewson, who assisted in the labours of 
the first eminent anatomical school in Lon- 
don, where anatomy was most ably taught 
by Dr. Hunter. And it is to the immortal 
Hunter that we are indebted for fully prov- 
ing the important doctrine, that the whole 
business of absorption is performed by the 
vessels which we are now considering. They 
have of late been injected in such great 
abundance, that they appear tally adequate 
to perform their office. 
If, as we firmly believe, these vessels 
be the only ones which perform the office 
of absorption, they must exist in every part 
