"I was sure of it," said Madame Adolphe to herself. She picked up the handkerchief and cried:
"Monsieur! Monsieur!"
"Well!" exclaimed the professor, made indignant by her watchfulness.
"I beg your pardon," he said, receiving the handkerchief.
"Have you any money?" asked Madame Adolphe with maternal solicitude.
"I need none," he replied naively, explaining thus the lives of all men of science.
"It depends," Madame Adolphe said. "If you go by way of the Pont des Arts you need one sou."