a test for determining the flash point of a volatile oil by use of a closed cup in which the oil is heated over a fixed flame and by use of a small movable flame that passes at regular intervals of temperature over the surface of the oil. a test for the stability of smokeless powder and similar explosives in which a ground sample is heated in a test tube with potassium iodide-starch paper, the time required for discoloring the paper being the measure of the stability.