When the food is received into the stomach, it is there subjected to the action of a solvent fluid, called the _gastric_ or _stomach juice_ (from γαστηξ, _gaster_, stomach), by which it is gradually converted into a soft greyish and pultaceous mass, called _chyme_, (from χυμος, _chymos_, humour or juice); whence the process is called _chymification_, or _chyme-making_. The chyme, as fast as it is formed, is expelled by the contractile power of the stomach into the duodenum (from _duodenus_, consisting of twelve, because it is supposed to be about twelve inches long), or first portion of the intestines. It there meets with the _bile_ from the liver, and with the _pancreatic juice_, which very much resembles the saliva, from the _pancreas_ or _sweet bread_ (πας, _pas_, all, and κρεας, _kreas_, flesh, it being of a fleshy consistence), a large gland which lies across the spine a little below the stomach, and is marked P in the wood-cut given in the chapter on Chylification. By the action of these two fluids, the chyme is converted into two distinct portions,--a milky white fluid named _chyle_ (from χυλος, _chylos_, chyle), and a thick yellow residue. This process is called _chylification_ or _chyle-making_. The chyle is then sucked in by absorbent vessels, extensively ramified on the inner membrane or lining of the bowels, and sometimes named, from the white colour of their contents, _lacteals_ or _milk-bearers_ (from _lac_, milk). These lacteals ultimately converge into one trunk, named the _thoracic duct_ or _chest-pipe_ (from its course lying through the _thorax_ or _chest_), and which terminates, as will be seen in a cut in Chapter VI., in the great vein under the clavicle or collar-bone, hence called _subclavian_ vein, just before the latter reaches the right side of the heart; and there the chyle is poured into the general current of venous blood. But although thus mingled with the blood, the chyle is not yet sufficiently capacitated for its duties in the system. To complete its preparation, it still requires to be exposed to the action of the air during respiration. This is accordingly done by its passing through the lungs along with the dark and venous blood, which stands in need of the same change. In the course of this process, both the chyle and the venous blood are converted into red, arterial, or nutritive blood, which is afterwards distributed by the heart through the arteries, to supply nourishment and support to every part of the body. Hence the change which takes place in the lungs is properly enough named _sanguification_ or _blood-making_.[18]