Smallpox. Smallpox was formerly one of the most feared of all diseases, because nearly every one who was exposed to it took the disease, and because a great number of those who were attacked by it died. A little over a hundred years ago it was found that a person could be protected against smallpox by vaccination. Now all that we have to do to escape the disease is to be vaccinated, and in countries where vaccination is practiced by all the people, smallpox is almost an unknown disease.

Scarlet fever. Some cases of scarlet fever are mild, but others are very severe. The germs are in the discharges from the nose, mouth, and eyes, but the scales from the skin are not dangerous, as was formerly supposed. Many bad after-effects follow this disease, and it should be carefully quarantined. It usually appears in from one to seven days after the germs are taken into the body; in most cases it is from two to four days. A patient is dangerous as long as the discharges from the eyes, ears, and nose continue. Usually cases of scarlet fever are quarantined for about fifty days.

Measles. Measles is a very catching disease. The matter from the nose and throat is especially dangerous, and the germs, like the germs of scarlet fever and smallpox, may be carried on clothing. No one with a cold should be allowed to come near a person who has measles, and the eyes should be shaded and carefully guarded during this disease.

A patient is usually dangerous to others for about three weeks after the time of the breaking out of the rash. The germs die out in a house in about two weeks. Measles ought to be carefully quarantined, for it is a most dangerous disease and causes about eight thousand deaths a year in the United States.

Mumps. One who has mumps is dangerous to others for about a week after the swelling has gone. The disease generally appears from thirteen to twenty days after the person has been exposed to the germs.

Boils and inflammation. Boils, carbuncles, pimples, bone felons, blood poisoning, and all inflammation in wounds and sores are caused by germs. Germs from a boil should not be allowed to reach other persons or the trouble may be spread. It is a common thing for a person with a boil to scratch the germs into the skin and bring on a whole crop of boils in other parts of his body.1

A cut or a sore should be tied up to keep germs from getting into it, and if particles of dirt have gotten into a wound they should be removed. Generally this can best be done by washing the wound with warm water, using when necessary a clean cloth rubbed on pure soap to wipe out the dirt. A fresh wound is often best treated by tying it up "in

1 A physician reports that a young girl who was suffering with a boil visited four different girl friends in four different families, and in each case the girl visited was attacked by boils,

the blood" and not opening it until it has healed. Carbolated vaseline or borated vaseline is often useful in treating small wounds and sores that have matter in them.

Tetanus. The germ of tetanus or lockjaw lives in the earth, especially about horse stables. It

FIGS. 108 and 109. A little time spent in cleansing and caring for a wound may save trouble later.

grows best in small, deep wounds and in wounds that get earth and dust into them. Deep wounds made by rusty nails or other unclean objects should be cleansed by a physician. Wounds made by toy pistols and firecrackers are lowed by tetanus and should be cared for by a physician. An antitoxin for this disease has been prepared which is almost sure to prevent it if used in time. This is now often given after Fourth of July wounds.

also likely to be fol

Other germ diseases. Among other diseases that are caused by germs may be mentioned chicken pox, German measles, acute (inflammatory) rheumatism, meningitis, cholera, leprosy, plague, and yellow fever. Germs also cause many diseases of animals. One of these diseases is rabies or hydrophobia, which man sometimes gets from the bite or scratch of a dog or cat. Some persons think that dogs take rabies because of a lack of water or because of hot weather, but this is not correct. They may have the disease at any time of the year, and they get the germ from the bite of another animal that has the disease. The Pasteur treatment will almost always prevent rabies if it is begun in time.

Questions: 1. How are the germs of malaria carried from one person to another? 2. How are scarlet fever and measles spread from one person to another? 3. Why is it necessary to quarantine these diseases? 4. What is the cause of boils and pimples? 5. Why is one boil often followed after a few days by others on other parts of the body? 6. What is the best way of caring for wounds of the skin? 7. Why is a small, deep wound dangerous unless carefully cleaned? 8. What is the cause of rabies?

Suggestions and topics for development: The importance of screening malarial patients to prevent infection of the mosquitoes, and of screening houses and sleeping under mosquito nets in malarial countries. The importance of vaccination. The foolishness of allowing communicable diseases to run through schools, because they are regarded as not very severe. The teacher should secure health bulletins and become familiar with the symptoms of any infectious diseases that threaten the school.

PREVENTING THE SPREAD OF DISEASE GERMS

SOMETIMES a farmer finds thistles springing up in his pasture year after year, even when he has carefully cut down all the thistles that are on his own land. Then the farmer knows that some of his neighbors are raising thistles and allowing the wind to blow the seeds about. A thistle grows only from a thistle seed, and as long as they keep appearing in the pasture the seeds must come from somewhere.

Disease germs, like thistles, do not come from nowhere. Every case of typhoid fever is caused by germs that come from another case of typhoid fever. Every case of whooping cough is caused by germs that come from another case of whooping cough. Every case of grip is caused by germs that come from another case of grip. The people who have these and other catching diseases scatter the germs abroad just as a thistle scatters its seeds. One very important way of checking the spread of these diseases is to destroy the germs that come from sick people and not allow them to get spread abroad.

Disinfectants. A disinfectant is something that kills germs. Light and drying are two of nature's disinfectants that are great enemies of germs. Fire is one of the best disinfectants for sputum and articles of little value, and boiling water kills disease germs at once. Germs may also be killed by bichlorid of mercury, quicklime, carbolic acid, lysol, and other substances that can be purchased at drug