370 Mr, Stephens's Suggestions for Ihe Improvement [Nov. 



time, are possessed of general knowledge sufficient for a cor- 

 rect comprehension of the subject ; and tliat with respect to the 

 majority, the lecturer is proceeding to build before the founda- 

 tion is really laid. The consequence is, that even the most 

 attentive and well inclined amongst his youthful auditory are 

 unable to follow him in his deductions, and are often thrown 

 into partial despair by the apparent difficulties of the study. 

 An instance or two will explain their peculiar embarrassments. 

 The first time they hear of specific gravity at a lecture, its uni- 

 versal relation to solids, fluids, and gases, will perhaps appear 

 incomprehensible to them; and all the necessary calculations 

 and corrections respecting temperature, atmospheric pressure, 

 and hygrometric moisture, tend to place the matter in greater 

 obscurity. But is the subject naturally obscure ? Certainly 

 not : the error lies in the mode of instruction adopted by the 

 lecturer, who brings forward barometers, thermometers, and 

 hygrometers, and applies them at once to his subject, taking 

 for granted that his auditors are all sufficiently informed of 

 their construction and use by a previous study of natural phi- 

 losophy ; which certainly ought to be the case, and certainly is 

 not, as education is generally managed. 



Again, when a lecturer treats of precipitation at the com- 

 mencement of his course as usual, he proceeds to exemplify it 

 in a way that must inevitably create a confusion of ideas in an 

 uninformed mind. For instance, he pours a solution of muriate 

 of barytes into another of sulphate of soda, points to a white 

 cloud appearing in the mixture as an evident precipitate, and 

 informs his class that it is produced by the double decom- 

 position which has taken place between the two salts, as the 

 result of their compound elective attraction, and that two new 

 substances are thereby formed — sulphate of barytes and muriate 

 of soda. In this short explanation a pupil is introduced to a 

 variety of new matters, ideas, and terms. He hears the word 

 *' precipitate " used for the first time as a noun, whereas he had 

 usually understood it as a verb active ** to throw downwards," 

 and is not a little confused to hear of precipitates forming 

 clouds, or rising to the surfaces of liquids. He may never 

 before have heard of the four salts concerned in the experiment, 

 and the only comment on the matter affi)rded him at the time 

 generally is — that what is commonly termed muriate of soda, 

 is properly a chloride of sodium ! — all of which remain to be 

 explained to him in future lectures. A hundred similar ii^tances 

 might be adduced. 



Thus every explanation of the laws which influence matter, 

 contains (accordmg to the present system of chemical instruc- 

 tion) something that a pupil who attends for the first time is 

 not prepared to understand, and frequent allusions to substances 

 he has not before heard of, but which he is told he will hear of 



