GERMANY IN SCIENCE 8 



Botany in the Carnegie Museum. This journal is one of a 

 great number, which are annually published for the purpose 

 of giving to the world the latest truths ascertained by botan- 

 ical research. 



In zoology the man who studies mammals is known as a 

 mammalogist; the man who studies birds is an ornithologist; 

 the man who studies fishes is an ichthyologist; the man who 

 studies insects is an entomologist. My friend, Lord Walsing- 

 ham,in an address some years ago, stated that there are no 

 less than three millions of species of insects in the world; and 

 so it has come about that the science of entomology has been 

 subdivided: a man who studies beetles is a coleopterist, and 

 the science for which he stands is coleopterology; the man 

 who studies butterflies and moths is a lepidopterist, and his 

 science is lepidopterology. I will not weary you. There are 

 recognized today a thousand or more different branches of sci- 

 entific research. 



Another valid distinction is between pure and applied 

 science. Pure science is knowledge sought for its own sake, 

 without reference to any use which may ultimately be made 

 of it. Applied science, on the other hand, involves the use of 

 ascertained truth in such a way as to promote inventions and 

 the arts. The student of physics, for instance, may devote him- 

 self, as did my former colleague, Dr. Samuel P. Langley, to 

 ascertaining the laws which govern the levitation of bodies 

 heavier than air, and in stating in the form of mathematical 

 formulae the amount of energy which is requisite to propel a 

 slanting plane against the air in such a way that it will lift up- 

 ward a given weight. The Wright brothers, taking the results 

 of Langley 's observations originally published by the Univeftsi- 

 ty of Pittsburgh, and applying the theoretical knowledge acquir- 

 ed, succeeded in producing an aeroplane which flies, as Langley 

 himself afterwards did. We must not forget that since Lang- 

 ley's death Glenn H. Curtiss has made successful flights in Pro- 

 fessor Langley 's aeroplane. This illustration serves to show 

 the distinction between pure and applied science. 



I come now to the theme, upon which it has been announced 



