Chapter 90 Oil
"It is not something important. This is only a poor quality resource used as a burning material by the majority of the masses who are unable to use magic. But there is a problem in its usage that diminishes its value as a fuel source. The thick black smoke it produces upon burning can mar any infrastructure and color it black. Moreover, the unpleasant smell and poisonous substances emitted during the burning process lowers its value in the eyes of those who have sufficient buying power. Only those who cannot buy better products like firewood opt for this cheap and difficult to use fuel." Bruce gave a long explanation regarding the fire water as he felt that Zach must be a young master of some hidden force and he might not have seen such a thing before in his life.