Another letter, December, 1843, to his son this time: “Tell Chappuis that I have bottled some 1834 bought on purpose to drink the health of the Ecole Normale during the next holidays. There is more wit in those 100 litres than in all the books on philosophy in the world; but, as to mathematical formulæ, there are none, I believe. Mind you tell him that we shall drink the first bottle with him. Remain two good friends.”
Pasteur’s letters during this first period at the Normale have been lost, but his biography continues without a break, thanks to the letters of his father. “Tell us always about your studies, about your doings at Barbet’s. Do you still attend M. Pouillet’s lectures, or do you find that one science hampers the other? I should think not; on the contrary, one should be a help to the other.” This observation should be interesting to a student of heredity; the idea casually mentioned by the father was to receive a vivid demonstration in the life-work of the son.
Pasteur often spent his leisure moments in the library of the Ecole Normale. Those who knew him at that time remember him as grave, quiet, almost shy. But under these reflective characteristics lay the latent fire of enthusiasm. The lives of illustrious men, of great scientists, of great patriots inspired him with a generous ardour. To this ardour he added a great eagerness of mind; whether studying a book, even a commonplace one--for he was so conscientious that he did not even know what it was to “skim” through a book--or coming away from one of J. B. Dumas’ lectures, or writing his student’s notes in his small fine handwriting, he was always thirsting to learn more, to devote himself to great researches. There seemed to him no better way of spending a holiday than to be shut up all Sunday afternoon at the Sorbonne laboratory or coaxing a private lesson from the celebrated Barruel, Dumas’ curator.
Chappuis--anxious to obey the injunctions of Pasteur’s father, who in every letter repeated “Do not let him work too much!” desirous also of enjoying a few hours’ outing with his friend--used to wait philosophically, sitting on a laboratory stool, until the experiments were over. Conquered by this patient attitude and reproachful silence Pasteur would take off his apron, saying half angrily, half gratefully, “Well, let us go for a walk.” And, when they were out in the street, the same serious subjects of conversation would inevitably crop up--classes, lectures, readings, etc.