IV 



oxygen the first week and if he gets through the term without 

 making a volcano or geyser he is lucky. 



This is not said to the disparagement of other studies. They 

 all have their peculiar merits which their professors are at liberty 

 to demonstrate. But chemistry has the advantage of most of 

 them in that it points toward the future and instigates to action. 

 The study of the history of man as written in books and of the 

 history of the earth as recorded in rocks gives one a sad sense of 

 irreparableness. What they deal with is dead and gone and all 

 that is left is their lesson which may or may not be applicable to 

 present problems. Meteorology is a discouraging science. 

 " People are always complaining about the weather but nobody 

 ever does anything about it." Astronomy reduces one to a state 

 of impotent awe. It is interesting of course to find out the struc- 

 ture of the solar system, but if you do not like it you cannot change 

 it. You cannot put Saturn in the place of Venus so as to get a 

 brighter evening star with two rings and eight satellites running 

 around it. You cannot even alter the inclination of the axis of 

 the earth so as to give the polar regions a chance to grow bananas. 

 But when you find out the structure of a chemical molecule you 

 can alter it to suit yourself. You can substitute a bromine for a 

 chlorine atom and hook up a carbon chain into a ring. 



In this field man is master of his material and the only limita- 

 tions to his power are his own ignorance and the innate intracta- 

 bility of the elements. Berthelot calls chemistry the most crea- 

 tive of the sciences, because it penetrates most profoundly into 

 the nature of things and deals with the infinitesimal parts of 

 which all substances are composed. The chemist begins by taking 

 things apart (analysis); then he proceeds to put them together 

 again (synthesis). Sometimes he puts them together in a differ- 

 ent way and then he gets something quite different, perhaps some- 

 thing that never existed on the earth before. Some 300,000 dis- 

 tinct substances are described in chemical dictionaries and only 

 a small fraction of these are to be found in nature. 



