Accidents

—When recently prepared charcoal is pulverized and laid in heaps, it is liable to absorb oxygen with such rapidity as to cause spontaneous combustion. This has been the cause of serious accidents at powder-mills, and hence it is important not to pulverize charcoal until it has been exposed to the air for several days. When charcoal has not absorbed moisture, and is mixed with oxidizing substances, it may be inflamed by violent shocks or by friction. This is the principal cause of the accidents which occur in the preparation of explosive mixtures which contain charcoal. See Gunpowder .