A CAUSE OF FIRES. The fact that wood rapidly oxidizes at certain high temperatures and becomes inflamed is well attested. The wood lagging which encircles locomotive boilers has frequently been found to have been burned to coke, and in some instances has actually taken fire on removing the outer casing. Here the temperature would not be over 300 degrees F., and though the heat would not of itseif be sufficient to ignite wood, rapid oxidation at such a temperature must soon bring about sufficient heat to cause ignition. The temperature at which wood takes fire is computed at 600 to 800 degrees F, The more oleaginous or resinous matter the wood contains the greater its susceptibility to inflammation,and this fact is to be made account of in all calculations.