"E'en so," Claudius says, in an approving tone. It's the tone of recognizing an apt pupil, or praising an attentive lover. "The basis of transmutation, with which alchemy is concerned. Thou see'st it in the twelve processes, in the four stages of a Magnum Opus, through which substances are changed from one form to another. But none of the change's energy can be created nor destroyed. It's often released in steam, in heat, in light. These are chemical reactions. I'm going to show you a chemical reaction, and then I'd like you to reproduce it."