Last winter, in the town where I was staying, there were large red cards fastened to the houses on almost every street. More than that, on each card there were seven letters so long and so black that people who walked on the opposite side of the street had no trouble in reading the word "measles." Everybody also knew what the sign meant, for it was as if the doctor had called aloud: "Measles are in this house. If you come in here, you will be in danger. You'd better stay away."

After the sign had been put up, I noticed that the neighbors obeyed the warning, for very few people besides the doctor himself went in and out of the house.

The fact is that the air in places where people have had certain diseases contains so many microbes of that disease that we are never willing to breathe it if we can help it. We are also most careful not to touch the people themselves, for we know only too well that microbes go as easily from a sick child to a well child as from a rotten apple to a sound one. It is a more serious matter, too, for the child; for though we can cut off a piece of apple that is getting rotten to save the rest of the apple, still it would be rather hard to cut off a piece of a child for the sake of saving the rest of him! It is easier and pleasanter not to let the microbes get a start in the first place. Children do, however, save themselves from a good deal of danger every day.

I sometimes wonder what a room full of children would say if I should ask them why they try to keep clean. Perhaps one would answer, "Mother makes me." Another might say, "I hate dirt"; and another yet, "Nobody likes me when I am dirty." These are pretty good reasons, although the teacher in the same room would probably say, "I keep clean because I want to keep well"; and this, in fact, is the most important reason of all.

Hands and faces and clothes that are not clean have more microbes on them than clean hands and faces and clothes. I wash my hands before I eat because, if I do not wash them, the microbes will go from my fingers to my bread or to anything else I touch. They will enter my mouth with my food, and I shall swallow every one of them. If disease microbes are there, they will go down just as easily as the others, and they may give me great trouble afterwards.

As we go from place to place in the city every day our hands touch things that other people have touched, and we do not know who those people were. We grasp the iron railing of a car to keep ourselves from falling but we never suspect that a man with some kind of disease microbes on his hands may have just let go that same rail and left his microbes there.

We push a shop door open with both hands; yet who knows what sort of woman with what sort of disease may have pushed it open two minutes before we came? Thus in a hundred ways we may gather up the worst of the city microbes. We may then reach home barely in time for dinner and, if we forget to wash our hands, we give all sorts of microbes from all sorts of people the chance to go into our mouths with our food.

Wearing gloves is quite a help, although even those who wear them are sometimes very careless. I have seen a gentle-looking, well-dressed woman with gloves on slip a penny between her lips for a moment. It was a dangerous thing to do, because who could tell what hand had held the penny before she held it, or what kind of microbes might be on it?

If her lips had been cracked or chapped, and if the microbes on the penny had been of the dangerous kind, she might have caught a dangerous disease. Lips that are slightly cracked are like apples that have their skins broken; if disease microbes get against them, they settle there at once and cause trouble.

We must not forget that most microbes are harmless, but we must be sure to remember that some of them do us such great harm that the safest thing is not to run any risks. It may be that the well-dressed woman whom I saw had never heard of microbes, for some people are quite behind the times in this matter.

Clothes need to be clean as well as hands,—also houses, schoolrooms, cars, and churches. The cleaner such places are, the safer we shall be; for wherever people live or go, wherever they breathe the air or die, there we are likely to find things that are soiled and microbes that are multiplying. Since we know all this we must try to keep clean every day; we must live in clean houses for the sake of keeping well.