V 
ON THE MESENTERIC VEINS. 33 
in which there is always a very limited quantity of water to be 
found. Hence, then, the small intestines, as i\\Q jejumwi and 
ileunij may be considered as those parts of the intestinal canal 
from which the more pure or better part of the cJiylej or new 
white blood, is absorbed ; while, on the contrary, the large in¬ 
testines, as the colon and cccciim, may be considered as those 
parts from which the more watery, or by far the least nutri¬ 
tious parts are absorbed or taken up ; and there is not the 
least doubt in my mind that this latter function is effected 
by the minute radicles of the mesenteric veins to a much greater 
extent than we have hitherto been aware of. 
If, therefore, not only veterinary, but likewise practitioners 
in human medicine, were to pay a little more attention to 
these subjects, and not to be led away with the idea that the 
lacteal vessels are the sole absorbents of the intestinal canal, 
and that the real veins have not any share whatever in that 
function, they would, in my opinion, be enabled more clearly 
to account for the different action of purgative medicines, as also, 
the function and diseases of that very important organ, the liver ; 
as it is a well known fact, that if the mesenteric veins really do 
absorb fluids from the intestines, as already stated, these fluids, 
before they can enter into the general circulation, to be passed 
olf again, must of necessity first of all circulate with the venous 
blood through the liver. I have not the least doubt of this 
being the case; and more particularly, when it is found, that 
those persons who are known to drink very large quantities of 
spirituous liquors, either with or without being combined with 
water, are always much more subject to diseases of the liver 
than those who live otherwise. 
If that which has been already announced is acknowledged 
to be generally correct, it will, also, in a very great measure, 
tend to explain the real 'nature and causes of the diseases of the 
liver, &c. of some of our animals, and more particularly of 
sheep, which so frequently occur in wet seasons, as well as when 
they are kept in very low wet situations, more particularly 
in the autumn of the year, and commonly denominated the rot. 
The food, under these circumstances, contains a much larger 
portion of moist watery matter than is really necessary for the 
healthy support of these animals, and the quantity of water 
imbibed with the food in such seasons being to a much greater 
extent than the more solid nutritive matter in the more dry 
seasons ; the necessary consequence is, that a much less quan¬ 
tity of real healthy chyle, or new white blood, is then made 
than when the food contains less moisture, and, of course, a 
greater quantity of more solid nutritious matter. Hence, 
VOL. VI. E 
