ON STUDIES MOST SUITABLE FOR ELEMENTARY SCHOOLS. 519 



acid (spirits of salt) and sulphuric acid (oil of vitriol) ; 'inQammablo air' burning 

 in ordinary air forms a liquid which on examination is found to be water, 

 ' Inflammable air ' hence called hydrog^en gas. 



Hydrogen gas, passed over hot oxides, e.g., copper oxide or lead oxides, 

 removes the oxygen forming water and the metal. Steam passed over iron forms 

 iron oxides and hydrogen gas. Water is hence oxide of hydrogen. Hydrogen 

 present in all food-materials, and, like carbon, undergoes oxidation in the body to 

 form water. 



The general properties of acids and alkalis ; h3'drochloric, sulphuric, and 

 nitric acids; sodium carbonate and caustic soda, lime, potash, ammonia. 



Acids and alkalis react with each other to form neutral substances called 

 'salts.' Prepare a sample of common salt by exactly neutralising caustic or 

 washing soda with hydrochloric acid (spirits of salts); the action of acids and 

 alkalis on colouring matters (litmus) and on fabrics. 



Differences between lime and chalk. The slaking of lime with water. The 

 lime-kiln. Loss of weight when chalk is converted into lime. Collection of 

 chalk gas. 



Action of acids on lime and chalk. Preparation of 'chalk gas' which is 

 found to be identical with carbonic acid gas. The weight or volume of ' chalk 

 gas ' obtained from one gram of chalk, marble, and kettle ' fur ' ; action of carbonic 

 acid gas on lime-water, and production of artificial temporarily hard water. 



Conversion of washing soda into caustic soda ; caustic soda converts insoluble 

 fat into soluble soap. 



Manufacture of soap ; different alkalis and different fata employed. The best 

 soaps for domestic purposes. 



The elements entering into the composition of the body — carbon, hydrogen, 

 nitrogen, and oxygen, with small quantities of sulphur, phosphorus, and the metals 

 calcium, potassium, magnesium, sodium, and iron. These occur chiefly in form ot 

 («) water, (b) organic matter, and (c) mineral salts. The products of combustion 

 of food-material and waste food are excreted ; this loss must be made good in 

 form of food ; to feed the body properly, without excess of any one type of food, 

 the diet must be mixed, and contain lean, fat, starch, and sugar. 



Revision lesson on food as the fuel of the body and the chief types of food- 

 stuffs. Lean, fat, and starch are all necessary for all the chief functions of food, 



A very simple treatment of the structure and function of the digestive system, 

 the mouth, stomach, intestines, liver, and pancreas. 



The principal changes that foods undergo in the human body ; how the food- 

 material gets into the blood stream. 



Tlie simple physiology of respiration and circulation of the blood ; the heart, 

 lungs, and circulation of the blood. 



Germs of disease (bacteria) ; conditions favourable to germ life ; the useful 

 work of germs in destroying refuse matter and rendering it available for plant 

 nutrition. The close relationship of dirt and disease ; the reasons for personal 

 and domestic cleanliness. 



APPENDIX C. 



Contracted Scheme of Work for Small Schools where the upper classes 

 are groiqjed for instruction in this branch. In order that the ground 

 covered in successive years should not he identical, tv;o 2}a7'allel schemes, 

 A and B, are suggested to be taught in successive years; the introductory 

 part of each scheme is the same, but different subject-matter is dealt with 

 in the latter part of the schemes. 



First Year. — Scheme A. 



Build up rectangular solids from cubes and deduce the rule for finding the 

 volume of a rectangular solid or space. The reasons for Felecting the cube as the 

 unit of volume. 



