Here is a before-and-after shot of a spontaneous combustion experiment we have been conducting. Spontaneous combustion can be a problem in biodiesel plants, where rags or sawdust soaked in biodiesel or oil can spontaneously ignite, causing serious fires. We want to know: under what circumstances will material soaked in biodiesel or oil spontaneously ignite? The mesh enclosure on the right contained sawdust soaked in boiled linseed oil (which tends to oxidize rapidly) and biodiesel. This was left out in the sun for five hours, and reached an internal temperature of 300 degrees C. It burned sometime during the night. Our experiments continue. For more information, contact Joe Thompson at firstname.lastname@example.org.