374* Mr, Stephens's Suggestions for the Improvement [Nov. 



the mischief is increased by his loss of that part of the lecture 

 which often passes unheeded during the continuance of his 

 perplexity, leaving an opening for fresh misunderstandings that 

 he may never afterwards have opportunity or leisure to remove. 

 Carelessness and dislike frequently follow in the train of con- 

 sequences, for no one can really love a science that is apparently 

 above his comprehension. 



Now, the doctrines of aggregation, affinity, decomposition, 

 combustion, absolute, specific, and latent caloric, &c. &c. which, 

 with their definitions and illustrations, form the substance of 

 several lectures at the outset of a scientific course of chemistry, 

 under the present arrangement, are poured into a young pupil's 

 ear long before he can possibly understand to what they relate ; 

 ignorant as he must be at first of the substances which he sees 

 employed in illustration. In the select elementary course, this 

 inconsistency should be carefully avoided, and these doctrines 

 introduced only when experiments directly illustrative of the 

 properties of each substance afl:brd opportunities of explaining 

 the accompanying appearances, and consistently entering on 

 the rationale of the matter. If no more be said at one time 

 than refers to experiments and exhibitions already made, the 

 progress of pupils will be real, rapid, and satisfactory. They 

 are always inclined to generalize and draw conclusions from 

 analogy (when they understand a subject,) as quickly as a pru- 

 dent teacher should wish : his chief care on this point will 

 therefore be to correct the notions they instinctively form, (or 

 most likely sanction them) by declaring the true state of the 

 case at the end of each series of experiments. It is judicious 

 at all times to give them opportunities and habits of exerting 

 their reasoning powers. The mind is pleased with its own 

 labours and discoveries, and memory fondly retains such little 

 triumphs long after the dogmas impressed by the voice of au- 

 thority have faded from recollection. 



Definitions without examples are, to the generality of young 

 persons, very perplexing and unprofitable. To say the truth, 

 they are matters rather of curiosity than utility in the present 

 improving and changeable state of our science ; and on weak 

 minds are often found to act like fetters which cannot easily be 

 shaken off when new lights are shining to stimulate them to 

 mental exertion. Since the discovery of the intimate connec- 

 tion of voltaic electricity and magnetism with chemistry, for 

 instance, all our old definitions of the science must in a great 

 measure go for nothing. 



In adherence to the principles advocated throughout, the 

 history of the science should be deferred till the end of the 

 first course, or better still, till the beginning of the second. By 

 this time the le(iturer will be intelligible when he adverts to 

 the^nqrgetic labours and brilliant inventions of his predecessors. 



