THEIR CAUSES, NATURE, AND PREVENTION. 175 



liver, the bile. The bile also contains a ferment which, to some 

 extent, also converts starch into sugar. It is alkaline, and in a 

 slight degree dissolves and emulsifies fats ; it is also supposed 

 to act as a natural purge in the intestines, and to prevent decom- 

 position by acting as an antiseptic. 



The pancreatic juice (succus pancreaticus) like the bile is 

 alkaline ; it converts starch into sugar to a much greater extent 

 than does the saliva, and as in the gastric juice, so in this, a 

 ferment (trypsin) exists which has the power of converting 

 albumen into peptones, it also splits up and emulsifies fats : both 

 bile and pancreatic juice convert a small quantity of fat into soap. 



Into the small bowels a secretion is poured, known as the 

 intestinal juice (succus entericus) which, in a modified degree, 

 assists the other juices mentioned. 



In the large bowels, acidity replaces alkalinity and certain con- 

 stituents of the food are rendered soluble, and probably digested. 



Some of the soluble matters of the food are absorbed partly 

 from the stomach, but more largely from the intestines ; the more 

 important constituents are mainly taken up from the small 

 intestines by the lacteals and the tributaries of the portal vein. 



It is evident, from what has just been stated, that perfect and 

 healthy digestion and the nourishment of the blood and the 

 tissues, depends entirely upon the perfect and healthy action of 

 the important organs to which I have referred. 



Fortunately, the salivary glands and the pancreas are rarely, 

 practically I may say never, found diseased in the sheep. The 

 stomach being of very complex arrangement is frequently 

 deranged ; and here I should observe that the three first com- 

 partments of the stomach of the sheep serve an useful purpose 

 in assisting to break up (comminute) and to soften the food 

 presented to them and thus prepare it for the more important 

 process to which it is subjected in the true digestive stomac'h — 

 the fourth. 



It would be well for animals, as also for ourselves, if we could 

 say the same of the liver as of the salivary glands and the 

 pancreas ; unfortunately, there is no gland in the body more 

 subject to functional and organic derangement than this. I say 

 unfortunately, not only on account of its secreting bile but on 

 account also of certain processes which go on in its interior 

 and upon which the support of life depends. 



In the liver, many of the constituents of the food — e.g., the 

 carbohydrates (not the fat) and, according to some authorities, 

 the peptones, are converted into a substance known as glycogen, 

 a sweet substance somewhat resembling sugar. Glycogen 

 is supposed to be produced by the action of a ferment and to 

 be stored up in the liver until required in the system, when it 

 is reconverted into sugar and discharged into the circulation 



