ABSORPTIO 



surface of the mucous coat, pass between the serous and 

 muscular coats, and proceed to the small glands or ganglions 

 of the mesentery/ As they emerge from these, they increase 

 rapidly in size, till they finally unite in a large trunk, which 

 passes up along the spine, and at last empties its contents 

 into the left subclavian vein near the heart. Many physi- 

 ologists are of opinion that the lacteals not only terminate 

 in the thoracic duct, but also in numerous veins in the ab- 

 domen. 



5. The chyle, which is the fluid taken up by the lacteals, 

 does not exist ready formed in the chyme, but isfformed or 

 manufactured out of the nutrient principles contained in it, 

 by a specific action of the lacteal vessels themselves} In 

 like manner, the sap which is contained in vegetables, does 

 not previously exist ready made in the materials which are 

 absorbed from the ground, but is formed by the peculiar ac- 

 tion of the roots. No chyle has ever been found in the 

 intestines. 



6. As the chyle passes on towards the heart, it undergoes 

 important changes. /It loses some of its albuminous quali- 

 ties ; while its fatty matter, its fibrin, and cruor, considera- 

 bly increase)) Its tendency to coagulate, also becomes 

 greater as it approaches the venous system, and it becomes 

 clearer and more transparent. What is the precise nature 

 of the change which the chyle undergoes in passing through 

 the glands is unknown. 



7. Absorption not only takes place from the small intes- 

 tines, but from the whole tract of the intestinal canal, inclu- 

 ding the mouth and sesophagus. But those vessels which 

 absorb chyle, are /chiefly found in the small intestines. It 

 is highly probable that alimentary substances may be directly 

 absorbed from the intestines, without undergoing any pre- 

 vious change or assimilation, like alcohol or water ; but that 

 in their passage through the absorbent system, they undergo 

 a species of digestion, and become in a good degree fitted 

 for the replenishment of the blood. To this, however, alco. 



25* 



