The Peep of Day (or A Series of the Earliest Religious Instruction the Infant Mind is Capable of Receiving) was a bestseller many times over in both Britain and America. Although Mortimer's grand-niece famously called it "one of the most outspokenly sadistic children's books ever written," millions of 19th-century children learned their first lessons about God from Mrs. Mortimer's stories.
The whole thing is worth a read, especially if you are interested in education in the 19th century, but my favorite part is right up front in the first chapter:
God does every thing. God gave you this little body, and he makes it live, and move, and breathe . . . God has covered your bones with flesh. Your flesh is soft and warm. In your flesh there is blood. God has put skin outside, and it covers your flesh and blood like a coat.Mrs. Mortimer also instructs children on being grateful for their bourgeois upbringings:
Now all these things, the bones, and flesh, and blood, and skin, are called your body. How kind of God it was to give you a body! I hope that your body will not get hurt. Will your bones break? Yes, they would if you were to fall down from a high place, or if a cart were to go over them. If you were to be very sick, your flesh would waste away, and you would have scarcely any thing left but skin and bones.
Did you ever see a child who had been sick a very long while? I have seen a sick baby. It had not round cheeks like yours, and a fat arm like this. The baby's flesh was almost gone, and its little bones were only covered with skin. God has kept you strong and well.
How easy it would be to hurt your poor little body! If it were to fall into the fire it would be burned up. If hot water were thrown upon it, it would be scalded. If it were to fall into deep water, and not be taken out very soon, it would be drowned. If a great knife were run through your body, the blood would come out. If a great box were to fall on your head, your head would be crushed. If you were to fall out of the window, your neck would be broken. If you were not to eat some food for a few days, your little body would be very sick, your breath would stop, and you would grow cold, and you would soon be dead. You see that you have a very weak little body.
The following chapter contains a long list of ways in which the reader's father might die suddenly, including falling off a ladder and getting kicked by a horse. I won't go through chapter by chapter — the rest of the book is mostly a life of Jesus with a few other Bible stories and a hair-raising account of the Apocalypse.
If you're interested in more from Mrs. Mortimer, I highly recommend Todd Pruzan's The Clumsiest People in Europe: Mrs. Mortimer's Bad-Tempered Guide to the Victorian World (2005), which reprints some of her geography lessons with commentary. Hilarious excerpts here.