no PHENOMENA, ATOMS, AND MOLECULES 



and notes of the trails used for the ascent that I could always return by 

 the same route. I thus climlDcd several mountains about 7000 feet high, 

 often requiring several days of repeated efifort before I could discover a 

 route that led to the top. Perhaps it is this experience which makes me even 

 today always wish to find my own way rather than be told. 



Until I was fourteen I always hated school and did poorly at it. At a 

 small boarding school in the suburbs of Paris, however, being an American 

 and having a friend who was influential with the head of the school, I was 

 freed from much of the absurdly rigorous discipline to which the French 

 boys were subjected. Thus, I could spend time alone in the school laboratory 

 and was encouraged by one of the teachers to learn to use logarithms and 

 solve problems in trigonometry, subjects not required by the curriculum. 



I have been fortunate in having many wonderful teachers. Three of 

 them have been recipients of this Perkin Medal. Whitaker and Chandler 

 were my teachers at Columbia and Whitney during the last eighteen years. 

 Prof. R. S. Woodward, at Columbia, in connection with his courses in 

 mechanics, was extremely stimulating and encouraged me to choose and 

 solve my own problems for class work instead of those required in the 

 regular course. 



I should like to see spontaneous work of this kind take a much more 

 prominent part in our educational system — at least for students who have 

 more than average ability. 



THE VALUE OF HOBBIES 



Very great benefit may be derived from hobbies. Probably each person 

 should have several of them. Recently I met a small boy, only six years 

 old, who had an overpowering, wide-eyed enthusiasm for collecting insects. 

 He weighed each one of them within a milligram, and then, after desiccat- 

 ing them thoroughly over calcium chloride, weighed them again. Many 

 elaborate notes and even correspondence resulted. I am afraid our uni- 

 versities, with their domiitories and other standardizations, tend to dis- 

 courage such wholesome individual activities. 



After talking of hobbies, I cannot resist the temptation to tell some- 

 thing about my own. Perhaps my most deeply rooted hobby is to under- 

 stand the mechanism of simple and familiar natural phenomena. I will give 

 only two illustrations, but these, I hope, will show how easy it is to find 

 around us simple phenomena that are not well understood. 



Every chemist knows that after he stirs a liquid in a beaker having a 

 precipitate in the bottom, the precipitate collects near the center. Probably 

 few know why this is so. It is not due to the slower velocity of rotation 

 near the center, nor to the slower motion with respect to the glass. This is 

 proved by the fact that if you put the beaker, with the precipitate in suspen- 



