ON TEACHING CHEMISTRY. 87 



of molecules. I must say that I think that " equivalents " should be used 

 for some time before any reference is made to atomic weights. As to 

 cramming a boy in the methods of writing equations, and finding how 

 mu.ch sulphuric acid and zinc will make so much hydrogen, I can only say 

 that, as the boy never attempts to carry it out in practice, and that if he 

 did he would find his calculations all wrong as compared with his results, 

 he had better leave them until late in his course, for their symbolic value 

 and, in many cases, real worthlessuess can only be estimated by a worker 

 in quantitative analysis. I think a boy's practical work should undergo 

 great alteration. At present he is examined in " simple salts," so of 

 course he is prepared for that by a system of "test-tubing " which teaches 

 him very little. He ought to start as far as possible with elements which 

 he knows, such as sulphur and iron, and he should prepare certain com- 

 pounds which contain them. He should then study the action of metals 

 on acids, and the salts formed; cases of oxidation and reduction; prepara- 

 tion and properties of gaseous elements and compounds.' 



LXX. ' In order that chemistiy may be a useful subject for the edu- 

 cation of boys, it seems to me necessary that it should be taught from ex- 

 periments involving measurements. Other experiments may be amusing, 

 Wt do not appear to afford food for severe or productive thought. It 

 seems to be now generally admitted that boys should be led as far as pos- 

 sible to make inferences from chemical experiments for themselves. If 

 they are to be taught the principal facts of chemistry in this way, it 

 follows that the experiments must be of the former nature. It seems 

 to be an evil that so much importance is attached in many examinations 

 to qualitative analysis, which appears, from an educational point of view, 

 to be one of the least valuable parts of the subject. The result is that 

 teachers are compelled to spend the time given to laboratory work on 

 this, to the detriment of experiments of a more instructive kind.' 



LXXI. ' For beginners the illustrated lecture, well supplemented by 

 periodical questioning, examination of note-books, &c., seems the only 

 feasible way of teaching large classes of, say, thirty or forty. When the 

 class is very small the lecture can be largely replaced by laboratory work, 

 in which the experiments are performed by each individual student. This 

 seems to me the best method ; but my experience is that it is impossible 

 to satisfactorily conduct large classes of young boys in the laboratory 

 except in such simple experiments as the action of metals on acids, 

 "which can be done with a few test-tubes and other very simple and 

 inexpensive apparatus, the breakages being too serious in an ordinary 

 school if it is attempted to go through the preparation of all the com- 

 moner gases with a large class of beginners, in laboratories as they are 

 usually arranged. I think more satisfactory results might be obtained 

 with such classes if a part of the laboratory were specially arranged for 

 the purpose, a bench (with only a few necessary reagents) in the form 

 of a semicircle being used, the students facing the teacher, who would 

 stand inside the semicircle. In such a class the students would all 

 perform the same experiment after being shown it by the teacher. With 

 rather more advanced students I think the separate system is better, all 

 students not working at the same experiment, as this obviates the 

 necessity of providing a large number of pieces of apparatus of the 

 same kind, and allows a quicker student to make more rapid progress. 

 I think it is very important that quantitative experiments should be 

 made as early as possible ; but here again my experience is that young 



