into your mouth, for without them your teeth could never have grown.
How are we to get out of this puzzle?

Suppose now, for a moment, that instead of phosphorus and lime,
thelittle workmen in your jaws had asked the blood for sugar to make the
teeth with. Fortunately this is only a supposition; otherwise I should
be in great fear for the poor teeth: they would not last very long.
Suppose, further, that instead of your eating the lump of sugar which
was destined to turn into a tooth, your mamma had melted it in a glass
of water, and had given it to you to drink; you could not say you had
eaten sugar, and yet the sugar would really have got into your stomach,
and there would be nothing very wonderful if the stomach had found it
out and given it to the blood, and the blood had carried it off to the
place where it was wanted. Now, allowing that the lump of sugar was
very small, and the glass of water very large, the sugar might have
passed without your perceiving it, and yet the tooth would have grown
all the same, and without the help of a miracle.

And this is how it was. In the milk which you drank as a baby there
were both phosphorus and lime, though in very small quantities. There
were many other things besides; everything of course that the blood
required for the use of its work-people, because at that time the
stomach was only receiving milk, and yet all the work was going on as
usual.

And therefore, my dear child, whenever in the course of our studies,
you hear me describe such and such a thing as being within us, say
quietly to yourself, "that also was in the milk which nourished me
when I was a baby."