202 Chemistry. [Lecture 81. 



is tough, and cuts like bees-wax, and, like it, 

 melts hi a gentle heat (99) into a transparent 

 fluid, and indeed with a less heat. With this 

 heat it may be melted in water ; but if the same 

 or even a lower degree of heat (43 for instance) 

 is applied in the open air, it melts, takes fire, 

 and burns, producing a bright white flame with 

 intense hefit *. Those who have been acci- 

 dentally burnt with it complain that it gives 

 more pain than any burn whatever. This is 

 partly from the intenseness of the heat, and 

 partly from the nature of the matter produced 

 during inflammation ; the phosphorus being con- 

 verted into an acid. 



The very small degree of heat necessary for 

 setting it on fire, shows the very strong attrac- 

 tion it has for the oxygen of the atmosphere. 



When the process of inflammation is going 

 on, the phosphorus is gradually changing its 

 nature. The oxygen is attracted from the at- 

 mosphere, and becomes united with it, convert- 

 ing it into an acid matter, then called phos- 

 phoric acid. 



The following is Dr. Thomson's process of 

 preparing phosphorus : Let a quantity of bones 

 be burned, or, in the chemical language, cal- 



* A trick is played with this phosphorus, viz. jetting 

 fi.ro to tow wrapped round a bottle, by pouring hot water 

 into the bottle, the outside of which is first rubbed with 

 phosphorus. 



