THE EEASON WHY. 05 



" V.'hen thou hast oaten and art full, then thou shalt bless the Lord thy God 

 for the good laud which he hath given thee." DETTT. vm. 



Because the liver secretes a fluid to assist in the digestion of 

 food. The liver is a gland a similar organ to the glands of the 

 mouth and it forms bile in the same manner that they form the 

 salivary juice. Only the liver is a much larger gland, and a much 

 greater quantity of blood passes through it. The liver pours its 

 secretion into the biliary duct (Fig. 49) to mix with the grey cream 

 as it passes onward, and to further dissolve it. But when the 

 stomach is excited by food which it cannot dissolve, and when the 

 owner of the stomach, disregarding its remonstrances, will persist 

 in over-eating, or in eating things that disagree with the system, 

 then the liver and the stomach sympathise, and the muscular 

 threads, or hands, that prevail all through the alimentary organs, 

 instead of moving onward, move backward, and throiv some bile 

 into the stomach to assist to dissolve and remove the excessive or 

 improper food. 



CHAPTER XLII. 



883. Why does some portion of the food ice eat nourish the 

 system, while other portions are useless? 



Because most food contains some particles that are indigestible, or 

 that, if digested, are innutritions, and not necessary for the system. 

 The liver is the organ by whose secretion the useful is separated 

 from the useless ; for when the bile enters through the duct (Fig. 

 49) and mixes with the grey cream coming from the stomach, it 

 remains no longer a grey cream, but turns into a mass coloured by 

 bile, having upon its surface little globules of milk, small, but very 

 white. Those minute globules of milk (chyle] are the nutritious 

 particles derived from the food ; the other portion, coloured with 

 bile, is the useless residue, or rather the bulk from ivhich the 

 nutrition has been extracted. 



884. Why does the milky, or nutritious matter, separate 

 from the innutritions, upon admixture ivith bile ? 



Because the bile contains an oily matter which repels the watery 

 milk of nutrition. 



