THE VETERINARY ART IN INDIA. 
547 
In their course from the bowels they unite and pass through 
a great number of glands, where it is supposed their contents re- 
ceive some change, rendering it more fit to unite with the blood in 
the circulation; after which they pass on, and, uniting, form a 
tube called the thoracic duct. This duct, passing up the breast, 
empties itself in the left jugular vein just before it passes into 
the vena cava ; which last vessel I before mentioned enters the 
right auricle of the heart, having brought back the exhausted 
fluid to be circulated through the lungs. Here the chyle assimi- 
lates, and becomes organized, if I may use the expression, into 
blood, by the new properties which it acquires in the lungs. 
Thus, the blood is continually supplied and nourished in quan- 
tity by the absorbents ; while it is continually receiving vital heat, 
and irritability or the principle of life, from the lungs. 
This supply is still further increased by the additions which it 
receives from the second set of absorbents, termed lymphatics ; 
and are employed through every part of the body to carry off 
the wasting particles and redundance, as muscular flesh, fat, 
fluids, bones, &c. This will be perhaps illustrated and render- 
ed more familiar by taking it in the following view : — Every one 
will allow, that. we cannot have a particle existing in our system 
at present which was there a few years past ; for every part of 
the body is continually wearing away from the abrasion of the 
fibres, &c., even in the most inactive life. The wasted particles 
are conveyed from the body by the lymphatics ; while there is a 
supply, or fresh deposit of matter, in exact proportion by the 
arteries ; except when the animal is growing — the deposit being 
then more than the waste. By this process in a few years there 
is a total change in both solids and fluids ; also during any disease 
in which the blood is not supported by food, the lymphatics are 
employed to imbibe the oily particles of fat, which they convey 
to the blood for its nourishment. 
There are many peculiarities in these vessels which are not ac- 
counted for. The chyle taken up by the lacteals of one animal 
differs not in the least from the chyle of another, even if one has 
been always fed with flesh and the other with vegetables ; which 
has given rise to many opinions concerning the power by which 
they absorb. It was formerly thought to be from capillary at- 
traction ; but this cannot be the case, for if it acted on this prin- 
ciple, it would alike absorb every thing fluid, whatever might be 
its quality ; and it is found that bile, &c., which is copious 
throughout the intestines, is never found in these vessels. For 
example, loaf sugar acts by capillary attraction ; for if it is held 
over, and just touching the surface of a thin fluid of any kind, 
