ABSORPTION OF FOOD 
415 
The indigestible part of the food is not absorbed, but 
continues to move through the small intestine into the 
large intestine, and on through the rectum. During this 
progress much moisture is absorbed, especially in the large 
intestine, which leaves the “ undissolved food ” harder 
and harder. The regular removal of the unused part of 
the food, fceces (fe'sez), is of much importance in main¬ 
taining health, because the bacteria living in the digestive 
tract cause the waste material to decay and the poisonous 
substances thus formed are injurious when absorbed into 
the blood. 
Foods normally remain in the stomach from one to five 
hours, and in the small intestine about four hours; while 
they may be from six to twenty-four hours in passing through 
the large intestine. 
We become hungry each day and feel relieved only after 
eating. A person frequently eats a large meal because of 
an extra amount of work that is to follow. But is he helped 
to do the extra work? Probably not, for the strength to 
do the work of to-day comes from the food eaten yesterday, 
or possibly the day before yesterday. The food, even after 
digestion is completed, must pass through many changes 
before it is built up into protoplasm. The actual building 
of the food into protoplasm is the process for which the word 
nourishment is used, and it should not be confused with 
absorption. 
Food as 
purchased 
contains 
' Edible portion f Water. 
e.g., flesh of meat, yolk and I 
white of eggs, wheat, flour, j 
• etc. [ Nutrients' 
Refuse 
l e.g., bones, entrails, shells, brain, etc. I 
Protein. 
Fats. 
Carbohydrates. 
Mineral matter. 
Vitamines 
(vi'ta-mlnz). 
Alcohol is made up of carbon, hydrogen, and oxygen. 
All proteins contain nitrogen in addition to these three. 
