ON STUDIES MOST SUITABLE FOR ELEMENTARY SCHOOLS. 518 



Determination of the solubility, i.e., the weight of solid dissolved in a given 

 weight (or volume) of its solution — of familiar substances, salt, soda, sugar, tea, 

 lime. Food materials must be rendered soluble before they can pass into the 

 blood stream and nourish the body. Small amount of solid nutritive material in 

 most beverages. 



Distillation of liquids — a double process of boiling and condensation. The 

 large amount of heat absorbed in converting water into steam. The heating 

 power of steam. Purification of a liquid by distillation. Production of alcohol 

 by distilling a fermented sugar solution. 



Burning of a candle in air confined over water ; the nature of the residual 

 'inactive air.' Moisture and a gas which turns lime-water milljy produced by the 

 burning candle. A candle will not burn in breathed air. 



The rusting of iron. Iron moistened and exposed to the air rusts and increases 

 in weight, but iron will not rust in boiled water. Iron rusting in a jar of air 

 causes the disappearance of about one-fifth of the whole. The residual gas is 

 'inactive,' but does not affect lime-water. Tlie same ' active' part of air is con- 

 cerned in burning, rusting of iron, and in breathing. 



Third Year {about 13 to 14 years of age). 



Experiments with siphon to see how rate of flow varies with difierence in 

 level of the liquids. Uses of the wphon for emptying tanks or reservoirs ; draw 

 curve connecting time of flow with average difference in level during flow. 



The volume of small irregular bodies found by weighing the water displaced 

 from a bottle by them. Relative density ot mercury, sand, shot, &c (The solid 

 should be weighed independently of the bottle so that pupils may see the water 

 displaced.) 



E.xtension of the principle of Archimedes to liquids other than water; a body 

 of known volume weighed in a liquid of known density to show that apparent 

 loss of weight is the weight of the liquid displaced. 



Modes of transference of heat ; simple experiments to illustrate conduction, 

 convection, and radiation, and the application of these to warming, clothing, &c. 

 The radiant heat of the sun. 



Expansion of a metal tube ; comparison of expansion of water and alcohol under 

 same conditions ; applications of expansion of solids and liquids to experiences of 

 daily life. 



Determination of expansion of unit -volume of air when raised 1° V>. Repeat 

 experiment if possible with coal-gas. Application of expansion of gases to 

 ventilation, explosives, winds, &c. 



The unit of heat; calculation of heat lost and gained by quantities of water 

 when cooled or warmed. Heat energy like matter indestructible. The heat 

 absorbed by a copper vessel in which hot and could water are mixed. 



Heat-capacity of metals ; the high heat.capacity of water compared with other 

 substances; the great importance of this fact in reference to climate and the 

 • retention of its heat by the human body ; heating by hot water. 



Comparison of amount of evaporation from a beaker of water on a fine and wet 

 day. Cooling efl^ect of evaporation ; the evaporation of perspiration on the skin, 

 and from the leaves of plants. Life possible in temperatures much above maximum 

 safe body temperature. 



Chemistry of the atmosphere. Air passed over heated copper examined. 



Air passed over heated phosphorus, sulphur, and carbon ; lead when heated 

 first converted into a yellow scale (litharge), then into a red scale (red lead). 



Composition of the air by volume, by burning phosphorus in a dry tube or 

 flask, and by the rusting of iron. 



Preparation of the ' active part' of air from red lead, and from a mixture of 

 potassic chlorate and manganese dioxide. Sulphur, carbon, and phosphorus burnt 

 in ' active air ' produce acids, hence the name oxygen. 



Oxygen passed over heated carbon ; properties of carbonic acid gas. 



Air synthesised by mixing oxygen with re.«idual air from the burning of 

 phosphorus and the rusting of iron. Combustion due to chemical union which 



1908. L L 



