Chapter 61

For instance, our senses tell us, and we know, that if you mix two known substances in a certain fashion, and in a certain proportion, say two portions by weight of the one and four portions by weight of the other, they will disappear, and a third totally different thing will appear in their stead. That is what happens when you try any one of a thousand chemical experiments. It is what happens when an electric spark is passed through a certain mixture of oxygen and hydrogen under certain conditions. We know that wi…