ON TEACHING CHEMISTRY. 299 
CHEMISTRY. 
Ten questions may be attempted in Chemistry and Physics, of which not more 
than four may be selected from Chemistry, and not more than three from each branch 
of Physics. 
UNG 
1. What are the meanings of the terms atom and molecule ? 
2. How is hydrogen obtained in a pure state, and what are its properties ? 
8. For what reasons is the chemical formula for nitric dioxide given as NO, 
while that of nitrous oxide is N,O? 
4, Give an account of the method of preparing nitric acid, and explain your 
answer by a chemical formula. 
5. What are the principal constituents of coal gas, and how may their 
respective formule be used to compare their densities ? 
6. State the effect of heating each of the following substances, and give the 
formule for the reactions :— 
i, Potassium Chlorate (IKCIO,). 
ii. Potassium Nitrate (IKKNO,). 
ili. Calcium Carbonate (CaCQ,). 
iv. Potassium Nitrite (KNO,). 
APPENDIX. 
Exercises illustrative of an Elementary Course of Instruction in 
Experimental Science. By Professor ARMSTRONG. 
The scheme put forward in the report presented last year by the Com- 
mittee sufficed to indicate the kind of instruction likely to inculcate habits 
of observing correctly, of reasoning from observation, and of setting new 
questions and obtaining answers thereto by experiment and observation: 
habits which it is now generally admitted are of great consequence in 
the struggle for existence, and which cannot be acquired except through 
training in the methods of experimental science. Nevertheless, it has 
been felt that detailed directions how to proceed were necessary for the 
use of the less experienced teachers, and that even those who fully sym- 
pathise with the proposals already made would welcome the more com- 
plete display of the system. I have therefore obtained the permission of 
the Committee to append the following suggestions to their report, in 
amplification of certain parts of the scheme already published. 
It is obviously impossible to sketch more than a small portion of a 
complete programme of instruction; the portion now offered is that 
appropriate to the earliest stage in which quantitative studies can be 
engaged in: its study can be commenced by children of fair intelligence 
when 9 or 10 years old. It is an essential feature of the scheme that it 
has reference to common things, the object being to lead children to 
engage in the rational study of the objects which are daily brought under 
_ their notice. 
Time to be devoted to Experimental Studies and Mode of Teaching.— 
Frequently during the past year the question has been put to me, ‘ How 
much time is to be devoted to such science teaching ?’ and complaint 
has been made of the difficulty of dealing with large classes of children, 
of keeping them employed, and of providing the requisite space and 
appliances. 
