J 826.] of the British System of Chemical Instruction, 371 



again. In consequence he is induced to postpone thought and 

 reflection to a more convenient opportunity, and thus acquires 

 the bad habit of hstening passively to what conveys no definite 

 notions to his mind. 



If, on the contrary, a lecturer with partial consistency exhibit 

 the phenomenon of precipitation, without informing his class 

 what the agents are which he employs, a youjig pupil, who is 

 exerting his faculties to learn the name and character of every 

 substance brought forward, feels particularly disappointed and 

 confused if he be stinted in this manner in the information 

 proper to an analytic course. 



Instead then of seeking to effect the double object of instruct- 

 ing the learned and unlearned at the same time, (which neces- 

 sarily produces one or both of the evils above mentioned) a lec- 

 turer who has studied " the conduct of the human understand- 

 ing ^' will endeavour to accomplish a separation of these two 

 classes, that he may prepare for each suitable information. The 

 instruction of the advanced student is sufficiently provided for 

 by the usual routine ; but to really benefit those commencing 

 the study, he will perceive the necessity of constructing a series 

 of lectures on a very different plan. His grand object in these 

 should be, — to convey elementary instruction in a style and 

 manner comprehensible to the plainest capacity, — excluding 

 every idea of display and artificial system which might inter- 

 fere with so desirable an end : — his surest way to attain a cor- 

 rect view of what such a course of instruction ought to be, is, 

 to suppose himself a pupil, and consider what kind of lectures 

 he would require in similar circumstances. 



Keeping this in view, he may readily frame a course of pre- 

 paratory lectures that shall proceed with ease and satisfaction 

 to all concerned. On the first day, each element may be dis- 

 played in succession, and its distinguishing properties familiarly 

 stated ; (avoiding its combinations, for it is impossible a lec- 

 turer can be understood, if he speak of them at first ;) — and by 

 the time all the simple substances in nature that we are ac- 

 quainted with are thus reviewed and classified, a pupil will be 

 astonished to find how few they are, and what an easy science 

 chemistry appears when clearly entered on. The elements (as 

 exhibited) may remain in their order on the table during suc- 

 ceeding lectures, in. which their primary combinations should 

 be experimentally explained, and completely gone through be- 

 fore the secondary combinations, or salts, are brought forward. 

 The latter must be described in their turn before the complex 

 animal and vegetable products can be consistently treated of. , 

 Whenever a compound is introduced, its elements may be 

 again referred to with effect, for here repetition is truly judi- 

 cious. If pupils have constant opportunities of turning their 

 attention to explanatory diagrams and groupes of the simpler 



2b2 



