194 REPORTS ON THE SATE oF screNCE.—1917. 
well worth while to inquire what is known of the early use of iron and to 
consider how, probably, the way to make it was first found out. It is made 
from ironstone—from iron ores as they are called, some of which are very 
like iron rust and others like hardened clay. It is made from an earth, in 
fact—by smelting or heating the earth together with charcoal or coke. You 
know that carbon burns in air—in the active part of it (Fire air) that is to 
say : does it perhaps associate with the Fire air as the iron does in rusting and 
does it release the iron in the ore when it is smelted with it by depriving it 
of Fire air? Questions such as these are not to be answered without further 
study. 
Stupy or Burning. 
As food and fire seem to be closely connected, it may be well now to study 
fire a little more fully and carefully. How do we produce fire—in the morning 
when lighting the fire; or- at any other time? You say at once—by striking 
a match. What is a match ?—nothing is more commonly used and yet few know 
anything about it. 
The easily inflammable substance—that which is fired by the heat developed 
by friction in drawing the match over the rough surface of the box—is 
phosphorus. What does the word mean—what language is it derived from? 
Phosphorus is made largely from animal bones. From bones, you say: can’t 
we get away from ourselves and our food even in studying the matches used 
in lighting the fire with the aid of which our food is cooked? Do all things 
move in a circle? 
Phosphorus, you will see, when it is put before you, is a yellow wax-like 
solid; it is always kept under water and must be handled with extreme care 
and only kept in the fingers during a short time, as it takes fire very easily 
and the burns it produces heal with difficulty. Why should it inflame sooner 
or later when taken out of water and not in water? Does this behaviour 
suggest anything to you? If so, make an experiment to verify your idea. 
What has this experiment taught you—does it not serve also to bring the match 
more closely into relationship with the iron stove than you before thought to 
be likely ? 
Very little phosphorus is used in matches—how does it burn alone? Care- 
fully dry a small piece, first on a duster and then on porous paper, place it on 
a brick or tile and touch it with a warm wire: at once it takes fire and burns 
brightly; as it burns, dense white smoke is given off. Try to stop the smoke 
from escaping by covering the burning phosphorus with a glass shade. Note 
what happens—describe the product. 
In burning other substances, you have found that the air is concerned— 
that, in part, it is ‘burnt’ as well as the inflammable substance: is the air 
concerned in the burning of phosphorus? Try. 
But as phosphorus takes fire so very easily, will it not be well to try to 
burn it alone to make sure that the air is concerned? It is possible to remove 
the air from a vessel by means of an air pump. Let us put a piece of carefully 
dried phosphorus into a strong globular flask, provided with a tightly fitting 
rubber stopper to which a glass tap is fitted : having exhausted the air by means 
of the pump and closed the tap, let us now cautiously heat the flask, where the 
phosphorus lies, over a small flame, sufficiently to melt the phosphorus : nothing 
happens. Now let us repeat the experiment with a strong flask full of air closed 
by a simple rubber stopper: the phosphorus takes fire but soon ceases to burn 
and apparently some remains unburnt. There was not much air in the flask— 
was any or all of it burnt along with the phosphorus? Think what happened 
when the phosphorus was exposed in air over water. What then will happen 
if the stopper be withdrawn from the flask while the neck of the flask is under 
water? See! 
It is clear therefore that whether it be merely exposed in air or burnt in 
air, the phosphorus kills, as it were, very nearly one-fifth of the air—its 
behaviour is much like that of all other burning substances, except that, to be 
precise, it is more like that of iron—which also gives a solid product, unlike the 
other substances which were burnt. But the air behaves alike to iron and 
phosphorus, seeing that one-fifth disappears under the influence of each, This 
