x LABORATORY TEACHING 247 



essential that he should know and take an interest 

 in the work of every man in his laboratory, whether at 

 the beginning or at the finish of his course. The pro- 

 fessor who merely condescends to walk through his 

 laboratory once a day, but who does not give his time 

 to showing each man in his turn how to manipulate, 

 how to overcome some difficulty, or where he has made 

 a mistake, but leaves all this to be done by the demon- 

 strator, is unfit for his office, and will assuredly not 

 build up a school. It is in the laboratory, and there 

 alone, that chemistry, like every other experimental 

 science, can be properly learnt, and it is by the 

 peripatetic teaching of the professor and his demon- 

 strators that the student benefits most. 



As regards elementary laboratory teaching my 

 idea is that, to be of any use, it must inculcate 

 method and accuracy both in theory and practice. 

 The student must be put on the right track, and 

 made to understand what he is doing, and why 

 he does it. Moreover, he must gradually gain 

 the power of exact observation, and of logical 

 inference. All these faculties are exercised and 

 developed in a properly organised and thorough course 

 of qualitative chemical analysis. The objections which 

 have been urged by some against this system as " mere 

 test-tubing" indicate to my mind a want of know- 

 ledge on the part of the critic of how to teach, and 

 what can be taught ; on the contrary, I venture to 

 assert that no elementary course of practical scientific 

 work is more useful, either in training the hand or the 

 head, than a properly conducted course of qualitative 

 analysis. This, however, presupposes that the exposi- 

 tion of the theory accompanies the practice of qualita- 

 tive analysis, and that a course of demonstrations, in 

 which the reactions and methods of separation are 



