On a certain evening, I studied the reaction between lead II acetate and potassium hydroxide in my house. When the candle flickered, light and shadow reflected on the wall. Put lead diacetate in a dish, slowly inject the liquid of potassium hydroxide, and for a moment, see its color change, or there is precipitation. I thought to myself, these two touch each other, and it is difficult to describe the beauty of their transformation. So I recorded the changes in detail, hoping to understand the truth of this, in order to explore the secrets of the combination of matter, and in the future, it can be widely used to add help to all kinds of matters, so that everything goes smoothly, and the skills are refined, so as to live up to the diligence of this research.