"11. Change wet clothing as soon as possible.
"12. Carefully avoid exposure to night air, in malarial districts.
"13. If necessary to go into an old vault or well, first introduce a burning candle. If the light burns low and finally goes out, carbonic acid gas is present and the place is unsafe to enter. Unslaked lime will absorb the gas and purify the air.
"14. Avoid walking on railroad tracks and icy sidewalks.
"15. When awake, very young children should never be left alone.
"16. Do not go, with loose hair or flowing garments, near dangerous machinery.
"17. Never touch gunpowder after dark.
"18. Never fondle a strange dog.
"19. Never light a fire with kerosene.
"20. Fill and trim your lamps in the day-time. Never trim or fill a lighted lamp.