4. If it costs ninety cents a year to feed a hen, find the net annual profit to this district from the egg production. CARE OF CHICKENS The method of developing conceptions of how to take proper care of chickens is based partly upon the pupils' experiences and partly upon a knowledge of the history of the original wild hens. Information can be gathered from the pupils as to the date of hatching of the earliest chickens and the date at which the pullets begin to lay. Chickens that are hatched in April begin to lay in November or December and lay throughout the winter when eggs bring the highest price. The original wild hens lived in the dry, grassy, and shrubby jungles of India. They were free to move about in the open air, and at night they perched in the trees, which sheltered them from rain. Hence may be inferred what kind of quarters should be provided for chickens. CARE AND FOOD OF CHICKENS Points developed Chickens must have plenty of fresh air without draughts. Heat is not necessary. Their quarters must be dry, clean, and well lighted. They require exercise. Their food must have in it the materials that are needed to make the substance of the egg. Breakfast: Wheat or corn scattered among straw--the scratching affords exercise. Dinner: Meat scraps, slaughter-house refuse, vegetables, sour milk, and rolled oats. Supper: As at breakfast. PHYSICAL SCIENCE PHASE OF NATURE STUDY The teacher is advised to read carefully the instructions and General Method of Experimental Science, Chapter I, before beginning the lessons in Physical Science. SOLIDS, LIQUIDS, AND GASES Arrange a collection of objects of various shapes, sizes, colours, and weights, as cork, glass, lead, iron, copper, stone, coal, chalk. Show that these are alike in one respect, namely, that they have a shape not easily changed, that is, they are _solids_. Compare these solids with such substances as water, alcohol, oil, molasses, mercury, milk, tar, honey, glycerine, gasolene. These latter will pour, and depend for their shape on the containing vessel. They are _liquids_. Compare air with solids and liquids. Such a material as air is called a _gas_. Other examples of illuminating gas, and dentists' "gas"; others will be studied in future lessons. Pupils may think all gases are invisible. To show that some are not, put a few pieces of copper in a test-tube or tumbler and add a little nitric acid. Watch the brown gas fall through the air; note how it spreads in all directions. Some gases fall because they are heavier than air; others rise because lighter. All gases spread out as soon as liberated and try to fill all the available space. Spill a little ammonia and note how soon the odour of the gas is smelled in all parts of the room. CHANGE OF STATE Heat some lead or solder in a spoon till liquid. Let it cool. Do the same with wax.