1906] Nature Study No. 36 89 



NATURE STUDY No. XXXVI. 



The Foundations of Chemistry as Seen in Nature Study. 

 (For Teachers Especially.) 



By John Brittain, Woodstock, X.B. 



Chemical Union. 



In order to teach effectively we must distinguish carefully 

 between the trivial and the important between the accidental 

 and the essential. We are apt to spend too much of the precious 

 school-time over the details which have little significance the 

 lifeless husks which enclose and conceal the living germ 

 thoughts. We think that we must do this in order to be 



thorough ; but we deserve no credit for thoroughness in doing 

 things which should not be done at all or which should be done 

 elsewhere or at another time. Let us rather devote our skill 

 and patience to the development, in natural and logical sequence, 

 ol the great facts and principles of nature and of life. Practice 

 and the habit of observation will ensure a sufficient knowledge of 

 details. 



At the basis of all the natural forms we see organic and 

 inorganic lies the fact of chemical union or combination. To 

 learn to distinguish it, by its effects, frcm mere mechanical mix- 

 ture, it is not necessary for the learners to wait until they have 

 become acquainted with the molecular and atomic theories. Only 

 very simple apparatus and cheap materia! are required for the ex- 

 periments which follow. 



Each member of the class is supplied with a small stick of 

 dry white wood. The sticks are held for a few seconds in the 

 flame of a spirit lamp. At once a scft black substance appears 

 in the heated part of the stick a substance which will mark on 

 paper and which will be found to be insoluble in water. The 

 pupils recognize this as charcoal which they may be told is a 

 form of carbon. Now the question is, where was the charccal 

 before the stick was heated? We could not see it before that 

 was done. 



It will be found, by holding the hand above the flame of the 

 lamp that no charcoal issues from it nor does it come out of the 

 surrounding air. Hence it must have been in the stick at first. 

 But why did the charcoal not then make the stick -black? 



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