Miscellanies. 347 



which either alone, or at least when combined with carbonic acid, 



are insipid, and insoluble in water." 



In teaching, it is highly important to avail ourselves of any knowl- 

 edge which the student may be fairly presumed to possess : we thus 

 proceed, from that which is more or less known, to that which is 

 partly or wholly unknown ; the student, to a degree, illuminates his 

 own path, and he thus follows, with more cheerful confidence, the 

 brighter light which his guide holds out before him. In the case in 

 hand, enough is known in common life of the properties of alkalies 

 and earths, to clear the first difficulties out of the teacher's way, and 

 thus to render it easy for him to proceed with their history. 



It appears therefore, highly expedient, not only that the alkalies 

 and earths should be retained, as distinct orders of bodies, and be so 

 exhibited to the pupil ; but that they should also be introduced to his 

 knowledge, as early as possible in the course of instruction ; nor is 

 there any serious logical inconsistency, or practical inconvenience in 

 such a step. The metals of the alkalies and earths, if described im- 

 mediately after their parent substances, will enable the teacher to 

 complete the most important part of the history of all those bodies, 

 without waiting for the distant period when the metals, as a class, 

 will come to be described, each in its proper place ; and when they 

 do thus come, he will, of course, revert to the metals that have been 

 already described ; he will enumerate them in the catalogue of me- 

 tallic bodies, and if any additional elucidations are necessary, he 

 can then, by comparison and analogy, present them in the most suc- 

 cessful manner, and their properties will, of course, be included in 

 the preliminary account of metallic bodies.* 



In the present state of chemical science, neither the analytical nor 

 the synthetical method, can, in a course of instruction, be exclusively 

 employed, with the greatest advantage. The synthetical is the most 

 expeditious and convenient, and it prevails, more and more, as science 

 becomes more extended, and acquires more certainty and precision : 

 the analytical, although slower, is the most satisfactory, and the most 

 interesting. Dr. Black taught principally in that manner ;f Dr. Hope 

 followed his steps ; and Dr. Murray wrote his System, and his Ele- 

 ments, as far as practicable, upon that plan. Both courses may be 



* So many metallic bodies are familiarly known, that we do not anticipate in men- 

 tioning metals, at any period of a course of chemical instruction, 

 t As appears by his printed lectures. 



