14 LOUIS PASTEUR 



your health," he wrote. "You are so lacking in 

 moderation in your work. Have you not already 

 injured your eyesight by your work at night? 

 Having arrived where you are you should be quite 

 happy and your ambition should be abundantly 

 satisfied." Chappuis, to whom Pasteur's father 

 had written, "Tell Louis not to work too hard," 

 doubtless exercised a wholesome influence over the 

 young student of science in his endeavor to lead 

 him into a more nearly normal mode of life. Chap- 

 puis' interests were chiefly in philosophy and lit- 

 erature, but his active mind readily assimilated the 

 subjects upon which his friend was fond of dis- 

 coursing. Young Pasteur's mind was so full of his 

 science and mathematics that he must find expres- 

 sion somehow. Realizing his father's educational 

 shortcomings and his strong desire for knowledge, 

 the son became the teacher of his father and he 

 undertook to carry on a sort of course of instruc- 

 tion by correspondence. In his delicacy about 

 assuming this role Louis wrote, "It is that you may 

 be able to serve as teacher to Josephine that I am 

 sending the work that you request." The father, 

 who would sit up late at night over the work as- 

 signed by the son, was a willing and industrious 

 pupil. "I have spent two days over trying to com- 



