"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."

"You are right," replied the man of science, as if he were retracing
instructions for a voyage to the North Pole. "I will go through the
Luxembourg, the Rue de Seine, the Pont des Arts, the Louvre, the Rue
du Coq, the Rue Croix-des-Petits-Champs, the Rue des Fosses-Montmartre.
It is the shortest route to the Faubourg Poissonniere."

"It is three o'clock," Madame Adolphe said. "Your sister-in-law dines
at six. You have three hours before you--Yes--you'll be there, but
you'll be late." She searched her apron pocket for two sous, which she
handed to the professor.

"Very well, then," she said to him. "Do not eat too much. You are not
a glutton, but you think of other things. You are frugal, but you eat
when you are absent-minded as if you had no bread at home. Take care
not to make Madame Vernet, your sister-in-law, wait. If you make her
wait, you will never be permitted again to go there alone, and it will
be shameful for you."

Madame Adolphe returned to the threshold of the little door and from
there watched her master. She had to cry to him, "To the right! To the
right!" for he was turning toward the Rue Notre-Dame-des-Champs.

"And yet he is a man of science, people say," she muttered to herself.
"How did he ever manage to get married? I'll ask Madame when I dress