"I know, I know. I am a filthy old man. But times have changed. No-body washes these days, and there are no conveniences. It is sixty years since I have seen a piece of soap. You do not know what soap is, and I shall not tell you, for I am telling the story of the Scarlet Death. 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. Our best ultramicroscopes could make a germ look forty thousand times larger. A mussel-shell is a thousand fingers like Edwin's. Take forty mussel-shells, and by as many times larger was the germ when we looked at it through a microscope. And after that, we had other ways, by using what we called moving pictures, of making the forty-thousand-times germ many, many thousand times larger still. And thus we saw all these things which our eyes of themselves could not see. Take a grain of sand. Break it into ten pieces. Take one piece and break it into ten. Break one of those pieces into ten, and one of those into ten, and one of those into ten, and one of those into ten, and do it all day, and maybe, by sunset, you will have a piece as small as one of the germs."

The boys were openly incredulous. Hare-Lip sniffed and sneered and Hoo-Hoo snickered, until Edwin nudged them to be silent.

"The woodtick sucks the blood of the dog, but the germ, being so very small, goes right into the blood of the body, and there it has many children. In those days there would be as many as a billion--a crab-shell, please--as many as that crab-shell in one man's body. We called germs micro-organisms. When a few million, or a billion, of them were in a man, in all the blood of a man, he was sick. These germs were a disease. There were many different kinds of them-more different kinds than there are grains of sand on this beach. We knew only a few of the kinds. The micro-organic world was an invisible world, a world we could not see, and we knew very little about it. Yet we did know something. There was the bacillus anthracis; there was the micrococcus; there was the Bacterium termo, and the Bacterium lactis--that's what turns the goat milk sour even to this day, Hare-Lip; and there were Schizomycetes without end. And there were many others. ..."