Sixth: _Dirt, which is an indirect cause of disease, must not be allowed to accumulate_. If your yard were full of dirt, garbage, and manure, it would not cause disease unless the germs of some disease became planted there. But such a place is an indirect cause of disease, in that it furnishes a fine place for germs to grow in. If a fly with typhoid germs on its feet were to alight in such a yard, the germs would be planted in a most favorable spot and would grow very fast. [Illustration: FIG. 41. A place that is an indirect cause of disease, since it furnishes a fine place for germs to grow in.] None of the disease germs like sunshine; neither do they like dry places. They die very quickly in the sunlight, and grow very slowly, if at all, in dry places; but in damp, dark places they grow very fast. Dirty back yards make ideal gardens for germs. Let a fly with germs on its feet alight in a clean yard where sunshine can reach every corner, and what chance will the germs have to grow? They will not even get a start. Hence, while disease cannot be caused by dirt, disease germs stand a very good chance of living where there is plenty of dirt and no sunshine. Filthy habits are on an equality with filthy conditions, and go hand in hand with them. One of the worst of habits, and a cause of much sickness, is that of answering Nature's calls in places other than the closet. =Questions.= 1. Why should you never make unnecessary visits to a sick person? 2. Why should you avoid anything used by a sick person? 3. Why should everything taken from a sickroom be scalded? 4. What should be done with all discharges from a sick person? 5. How is dirt a source of disease? =Remember.= 1. Unless it is necessary, do not go into a room where anyone is sick. 2. Never sleep in a room with a sick person. 3. Never eat from a spoon or plate that has been used by another. 4. Boil all the articles taken from the room of a sick person. 5. Always wash your hands after touching a sick person or anything that comes from his room. 6. Sunshine kills germs; let the sunshine into every corner of your house. CHAPTER XVIII FLIES AS CARRIERS OF DISEASE [Sidenote: How germs get into our bodies] Disease germs get into our bodies in three principal ways: they are eaten with our food; they are taken in with the air we breathe; and they get in through breaks in our skin, even though these breaks be very small, as when made by the bite of a mosquito or other insect. [Sidenote: How germs get into our food:] [Sidenote: (_1_) From the air] How do germs get into our food or drink? You must remember that these germs are extremely small, so small that many of them can be carried by a particle of dust that you can see only in a ray of sunshine. When the germs become dried, they float about on these particles of dust, the dust alights on our food, which is moist and warm, and the germs immediately begin to grow. [Sidenote: (_2_) From the hands]