"—did a splendid job, I have no doubt." Tyrion placed the jar he'd been holding back among its fellows. They covered the table, standing in orderly rows of four and marching away into the subterranean dimness. And there were other tables beyond, many other tables. "These, ah, fruits of the late King Aerys, can they still be used?"
"Oh, yes, most certainly…but carefully, my lord, ever so carefully. As it ages, the substance grows ever more, hmmmm, fickle, let us say. Any flame will set it afire. Any spark. Too much heat and jars will blaze up of their own accord. It is not wise to let them sit in sunlight, even for a short time. Once the fire begins within, the heat causes the substance to expand violently, and the jars shortly fly to pieces. If other jars should happen to be stored in the same vicinity, those go up as well, and so—"