You know what sickness is. We called it a disease. Very many of the diseases came from what we called germs. Remember that word—germs. A germ is a very small thing. It is like a woodtick, such as you find on the dogs in the spring of the year when they run in the forest. Only the germ is very small. It is so small that you cannot see it—” Hoo-Hoo began to laugh. “You’re a queer un, Granser, talking about things you can’t see. If you can’t see ’em, how do you know they are? That’s what I want to know. How do you know anything you can’t see?” “A good question, a very good question, Hoo-Hoo. But we did see—some of them. We had what we called microscopes and ultramicroscopes, and we put them to our eyes and looked through them, so that we saw things larger than they really were, and many things we could not see without the microscopes at all.