Insects and Foods.--In the summer our houses should be provided with screens. All food should be carefully protected from flies. Dirty dishes, scraps of food, and such garbage should be quickly cleaned up and disposed of after a meal. Insect powder (pyrethrum) will help keep out "croton bugs" and other undesirable household pests, but cleanliness will do far more. Most kitchen pests, as the roach, simply stay with us because they find dirt and food abundant. Use of Ice.--Food should be properly cared for at all times, but especially during the summer. Iceboxes are a necessity, especially where children live, in order to keep milk fresh. A dirty icebox is almost as bad as none at all, because food will decay or take on unpleasant odors from other foods. [Illustration: The wrong and the right kind of garbage cans.] Disposal of Wastes.--In city houses the disposal of human wastes is provided for by a city system of sewers. The wastes from the kitchen, the garbage, should be disposed of each day. The garbage pail should be frequently sterilized by rinsing it with boiling water. Plenty of lye or soap should be used. Remember that flies frequent the uncovered garbage pail, and that they may next walk on your food. Collection and disposal of garbage is the work of the municipality. [Illustration: The culture (_A_) was exposed to the air of a dirty street in the crowded part of Manhattan. (_B_) was exposed to the air of a well-cleaned and watered street in the uptown residence portion. Which culture has the more colonies of bacteria? How do you account for this?] School Surroundings.--How to Improve Them.--From five to six hours a day for forty weeks is spent by the average boy or girl in the schoolroom. It is part of our environment and should therefore be considered as worthy of our care. Not only should a schoolroom be attractive, but it should be clean and sanitary. City schools, because of their locations, of the sometimes poor janitorial service, and especially because of the selfishness and carelessness of children who use them, may be very dirty and unsanitary. Dirt and dust breed and carry bacteria. Plate cultures show greatly increased numbers of bacteria to be in the air when pupils are moving about, for then dust, bearing bacteria, is stirred up and circulated through the air. Sweeping and dusting with dry brooms or feather dusters only stirs up the dust, leaving it to settle in some other place with its load of bacteria. Professor Hodge tells of an experience in a school in Worcester, Mass. A health brigade was formed among the children, whose duty was to clean the rooms every morning by wiping all exposed surface with a damp cloth. In a school of 425 pupils not a single case of contagious diseases appeared during the entire year. Why not try this in your own school?