"Look here, all of you," he said entreatingly, as soon as Nana had gone into the bathroom.

"I have just thought of a splendid joke.

I shall pour my medicine into Nana's bowl, and she will drink it, thinking it is milk!" It was the colour of milk; but the children did not have their father's sense of humour, and they looked at him reproachfully as he poured the medicine into Nana's bowl.

"What fun!" he said doubtfully, and they did not dare expose him when Mrs.Darling and Nana returned.
"Nana, good dog," he said, patting her, "I have put a little milk into your bowl, Nana." Nana wagged her tail, ran to the medicine, and began lapping it.

Then she gave Mr.Darling such a look, not an angry look: she showed him the great red tear that makes us so sorry for noble dogs, and crept into her kennel.
Mr.Darling was frightfully ashamed of himself, but he would not give in.