112 ° Protection of Persons from Fire. 
facts deserve the attention of all who have charge of custom houses 
and other depots of merchandize. 
It is well known that many coal mines inflame spontaneously. 
Certain kinds of coal have this property, and the maritime police of 
certain countries prohibit its transportation in ships. — - 
Sulphurous turf (and there is much of it) is also the cause of spon- 
taneous fire, and requires the same precautions as coal of the same 
quality. In both cases, it is the abundance of sulphuret of iron, and 
its decomposition by moisture, that produce the heat requisite for 
combustion. ‘The fermentation of hay and straw may set fire to 
arns. If the mass be sufliciently moist, no circulation of air will 
prevent the effect. 
As the art of building advances, the causes of destruction are 
more and more removed. Incombustible materials are more sought 
after. ‘The superb dock ware-houses of England are almost entirely 
of cast iron. In private dwellings, means have been tried to render 
wood incombustible, or very slow of combustion and easily extin- 
guished. These consist of some external cement or covering, or of 
a substance which penetrates the wood, without weakening it; but 
this art has not yet attained perfection. 
It is doubtless impossible to prevent fires altogether. Pliny, m 
speaking of the ravages which fire had just occasioned in Nicomedia, 
proposed to Trajan to form an establishment of one hundred a 
fifty select and skilful men, to be charged with the special duty of 
extinguishing fires and assisting the sufferers: this is the first idea of 
the institution of firemen. 
In general, the means of extinguishing fires are the more effica- 
cious the sooner they are applied. Let every obstacle, therefore, 
which can retard the operations of firemen, and the arrival-of their 
apparatus, be as far as possible removed. The eyes of magistrates 
should be particularly directed to this point. 
How extensive soever a conflagration may become, the well di- 
rected courage of the firemen may prevent a mass of distress: 
Though a whole town should take fire, there will be quarters where 
assistance would not be useless; but the power of man, as well a 
his foresight, has its limits. When Franklin had found the secret of 
preserving buildings from the ravages of lightning, he acknowledged 
that he made no pretensions to the means of preventing the & 
croachments of another deluge, or of a universal conflagration. But 
notwithstanding this limitation.of power, the world will not renounce 
e use either of lightning rods or of fire engines. 
