26 CUDPEPER’s' ENGLISH’ PHYSICIAN, 
fone external ‘thick one, borrowed from the neighbouring parts, when either’ they 
are fafpended and! carried a long way without the bowels and mufcles} or, “when 
they re(t upon hardbodies, “This happens in the abdomen.to the veins and arteries 
ftom the peritowendms and in the cheft from the pleura, Their ufeis'to receive the 
blood not fuficiently elaborated from the arteries, and’to return i€ to the liver and 
heart; there co bé’niore perfeétly concocted. For neither is the venab blood) nordo 
'the-veins carry any thing ufeful for nutrition s but they bring back’all the blood to 
othe heart, only by-circblation, either mediately by the liver, asthe mefaraic veins} or 
© jmmediately, as the-savey/and that either from the whole body, from. the fmalleft 
"branches to the gréateftp by the upper ant lower branch, or, from the liver, whe- 
ther it be there generated; or is derived from the mefaraics and arteries, Hence it 
‘appears, that the veins carry and re-carry the blood to the liver; and to this end 
“the valves of the veins do confpire, which are fo contrived, that they ftand all wide 
‘open towards the heart, and afford an eafy paflage from the fmalleft veins ‘tothe 
‘greatett, and from thence to the heart} but, from the heart’ and ‘great’ veins’ being 
. ‘hut, they fuffer nothing to go: back. The liver fends only t to the t hearty the heart 
all parts, and cannot now be sn fbaiy? repaired by diet; nor return back to: thaeidane 
by the mitre-fathioned valves of the aerta, nor abide ftill in the arteries, whieh are 
continually moving forward the’ fame; nor laftly, that there can be'fo much dpent 
by the parts to ‘be nourifhed: it neceflarily follows, that what remains over and 
“above is brought back again to the heart, and enters the veins by circulation.” The 
fubftance of the veins is membranous, that they may the more eafily ftretch and 
“fhrink in again : they have only one tunicie which is proper to them, whieh is thin 
“ahd rare’; it is fo thin, that through it the blood may be received after chesparts are - 
“nourithed, and fo be re-carrjed to the heart, tobe there again perfected. “Thewalves 
‘of the ‘veins ‘are little foldings, or gates : they are made of moft thin little:mem- 
“branes in the inner cavities ‘of the veins, and certain particles as’ iv were of the 
S€eats of 'the’’veins : they are fituated in the cavities of the veins chiefly of the 
—e the armis and legs, after the glandules of the arm-holes and groins, 
‘beginning prefently after the rifes of the branches, but nor in the rifes themifelves 5 
oineiaiabd adgiar them in the external {mall veins, becaufe theyneed them nots 
‘nor in the jugulars-(except two in the inner orifice, looking from above downwards), 
-becaufe the blood doth hardty afcend upwards; ‘nor in-the ‘vena ca’va,’ ‘becaufe’ the 
valves in the divarications do ‘fufficiently hinder the tegre(s of the blood: theyware 
alfo found in'the emulgents, ‘and in the branchesof the mefentery,: looking towards 
the vena cava and’ porta; as aifo in the milky ‘veins! “They “all of them Jook' the 
fame way, ‘one after anather, -eowards the hitare anid ate placed: at convenient dic 
hae 2 tances, 
