62 LOUIS PASTEUR 



studies are not readily forgotten, if they ever are. 

 It is almost as if, in order to teach the geography 

 of a country, one causes a student to travel in it. 

 That geography is preserved in the memory because 

 one has seen and been in contact with the places. 

 Similarly, your sons will never forget what is con- 

 tained in the air we breathe when they have 

 analyzed it, when in their hands and under their 

 eyes the admirable properties of its elements have 

 been revealed." 



The relative merits of studies in pure and in 

 applied science have been the subject of no end 

 of learned disquisitions. Lille is in the center of 

 an industrial region and its inhabitants looked to 

 the University for scientific information of a prac- 

 tical kind. The words which Pasteur addressed to 

 the public on the appropriate occasion of his in- 

 stallation are well worthy of quotation. "Without 

 theory practice is but routine engendered by habit. 

 Theory only is able to cause the spirit of inven- 

 tion to arise and develop. It is important that 

 you, above all, should not share the opinion of 

 those narrow spirits who disdain everything in 

 science that has no immediate application. You 

 may recall the charming response of Franklin when 

 he took part in the first demonstration of a purely 



