You don't know what soap is, and I won't tell you, because I'm telling you the story of the scarlet plague. You know sickness; we used to call it disease. And a lot of diseases were caused by what we used to call germs. Remember that word: germs. A germ is a very small thing. It's like a wood tick, the one you find on dogs in the spring when they're running around in the woods, but germs are very small. They're so small you can't even see them..."
Ho-Ho burst out laughing.
"You're a strange man, Grandpa, talking about things you can't see. If you can't see them, how do you know they're there? That's what I want to know. How do you know anything you can't see?"
"That's a good question, Ho-Ho, a very good question. But we've already seen some of them. We had instruments we called microscopes and supermicroscopes, which we would place over our eyes and look through to see things larger than they really were. There were many things we could not see at all without microscopes. The best microscopes made a germ appear 40,000 times larger than it really was. An oyster shell is like a thousand fingers like Edwin's. Take 40 of these shells, and that gives us the number of times we could magnify the germ under the microscope. Next, we had other methods. By what we called moving pictures, we could make this germ, which was now 40,000 times larger than its natural size, much larger and much larger by magnifying it thousands and thousands of times. In this way, we could see all the things that our eyes alone could not see. Take a grain of sand and divide it into ten parts. "And take one of these ten parts and divide it into ten parts, and then take one of those parts and divide it into ten parts, and then take one of those parts and divide it into ten parts, and then take one of those parts and divide it into ten parts, and then take one of those parts and divide it into ten parts, and so on all day long, and perhaps by sundown you will have a small part the size of a germ." The boys were clearly skeptical. Hair-lip snickered, and Ho-ho chuckled, until Edwin nudged them to shut them up.