CHAPTER II 



LESSONS IN CHEMISTRY 

 1. THE STUDY OF A MATCH 1 



A SPLINTER of soft pine wood tipped with a mixture of 

 phosphorus, sulphur, and other ingredients is one of the 

 commonest necessities of every-day life. We light these 

 matches a dozen times a day and throw them away half- 

 burned, never thinking that we might learn from this ap- 

 parently simple process many of the fundamental principles 

 of chemical science. 



Phosphorus. If in a dark room I draw the tip of a 

 match across my finger, there is left behind a luminous 

 streak. This is caused by the slow burning of phos'pho-rus. 

 To understand what has taken place we must experiment 

 with phosphorus alone. In its pure state it is a yellowish 

 white, waxy solid. It is usually manufactured in sticks 

 about the size of one's finger, and these, because of the great 

 inflammability of phosphorus, are always kept under water. 



Suppose we cut off a bit of phosphorus about the size of 

 a pea, and hold it on the knife tip. 2 As it becomes dry it 

 gives off little streams of white smoke, and the piece grad- 

 ually diminishes in size. If it is rubbed vigorously against 

 a rough surface, the waxy mass bursts into a bright yellow 

 flame and soon disappears. 



Oxid of Phosphorus. Let us now inquire somewhat 

 closely into this process of burning. Our earth is sur- 

 rounded by a mixture of gases that form the atmosphere. 



1 See Peabody's "Laboratory Exercises," No. 1. Holt & Co. 



2 Phosphorus should never be handled with the fingers. 



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