17.  Effects of Alcohol upon the Liver.—­The liver, as well as the stomach, is greatly damaged by the use of alcohol.  You will recollect that nearly all the food digested and absorbed is filtered through the liver before it goes to the heart to be distributed to the rest of the body.  In trying to save the rest of the body from the bad effects of alcohol, the liver is badly burned by the fiery liquid, and sometimes becomes so shrivelled up that it can no longer produce bile and perform its other duties.  Even beer, ale, and wine, which do not contain so much alcohol as do rum, gin, and whiskey, have enough of the poison in them to do the liver a great deal of harm, and to injure many other organs of the body as well.

SUMMARY.

{Eating too fast. 
{Eating too much. 
{Eating too frequently. 
{Eating irregularly.
1.  CAUSES OF INDIGESTION. {Eating when tired. 
{Eating too much of sweet foods. 
{Eating too many kinds of food
at a meal. 
{Using iced foods or drinks.

2.  Irritating substances and things which are not foods should not be eaten.

3.  The teeth must be carefully used and kept clean.

4.  Tobacco-using does the stomach harm, and sometimes causes cancer of the mouth.

5.  Alcohol injures the gastric juice, and causes disease of the stomach and the liver.

CHAPTER X.

A DROP OF BLOOD.

1.  The Blood.—­Did you ever cut or prick your finger so as to make it bleed?  Probably you have more than once met with an accident of this sort.  All parts of the body contain blood.  If the skin is broken in any place the blood flows out.

2. How many of you know what a microscope is?  It is an instrument which magnifies objects, or makes them look a great deal larger than they really are.  Some microscopes are so powerful that they will make a little speck of dust look as large as a great rock.

3.  The Blood Corpuscles.—­If you should look at a tiny drop of blood through such a microscope, you would find it to be full of very small, round objects called blood corpuscles.

4. You would notice also that these corpuscles are of two kinds.  Most of them are slightly reddish, and give to the blood its red color.  A very few are white.

5.  Use of the Corpuscles.—­Do you wonder what these peculiar little corpuscles do in the body?  They are very necessary.  We could not live a moment without them.  We need to take into our bodies oxygen from the air.  It is the business of the red corpuscles to take up the oxygen in the lungs and carry it round through the body in a wonderful way, of which we shall learn more in a future lesson.

6. The white corpuscles have something to do with keeping the body in good repair.  They are carried by the blood into all parts of the body and stop where they are needed to do any kind of work.  They may be compared to the men who go around to mend old umbrellas, and to do other kinds of tinkering.  It is thought that the white corpuscles turn into red ones when they become old.