70 



SCIENCE 



[N. S. Vol. LII. No. 1334 



How are tte lines in the spectrum to be ac- 

 counted for? And how does an atom radiate 

 energy, anyway? It is a delightful situation 

 for the mathematical physicist to face, for 

 he has already achieved a very solid foothold, 

 and we may be sure he will not be slow to 

 push his advantage. 



If the private affairs of the atom belong to 

 the domain of the physicist, their social affairs 

 belong to the chemist. And what tremen- 

 dously social creatures they are! Few of 

 them are content to live by themselves. The 

 vast majority of them cling more or less 

 tenaciously to other atoms or groups of atoms, 

 and these groups are the chemists' molecules, 

 the smallest particles of what we call ordinary 

 matter. This grouping is not a mere random 

 affair. The atoms exhibit a distinct choice 

 not only as to their associates but as to the 

 manner in which they will associate together. 



Just as the physicist has his problems as to 

 the structure of the atoms so the analytical 

 chemist is busy breaking up the almost in- 

 finite variety of molecules he finds about him 

 to learn what atoms enter into their structure 

 and what are the relations which exist be- 

 tween those atoms. In this endeavor he has 

 been highly successful and the great majority 

 of molecules he can read as an open book, 

 but the subtile strain of carbon molecules 

 will doubtless tax his ingenuity for a long 

 time to come. On the other hand, the syn- 

 thetic chemist is slowly learning how to coax 

 the atoms into those particular groups which 

 either his theory tells him are possible or for 

 which nature herself has already furnished 

 an example. In the domain of ordinary 

 masses the architect and engineer, the painter 

 and sculptor and the skilled artisans of a 

 thousand varieties have learned how to build 

 up their structures to suit their various pur- 

 poses. But the physicists have not yet 

 dreamed of building up an electron nor an 

 atom. The biologists have little hope of ever 

 constructing a living organism. The geolo- 

 gists are content to examine their rocks and 

 to make the past live again in their vision; 

 while the astronoraers in the very nature of 

 things must maintain a respectful distance 



from, the objects which engage their interest. 

 Outside the domain of ordinary masses it is 

 the synthetic chemist alone who can engage 

 in the process of physical construction, the 

 building up of those units which are the ob- 

 ject of their study. The world is very greatly 

 their debtor to-day, and this debt will in- 

 crease enormously as the chemists rise higher 

 and higher in their ability to control the 

 groupings of the atoms in the molecules. 



Our greatest familiarity and closest in- 

 timacy with nature naturally lies in that 

 portion of the scale of physical units to which 

 we ourselves belong, viz : ordinary masses. 

 It is here that the geologists and biologists 

 are at home. But so infinitely varied is the 

 aspect here presented to us that these sciences 

 divide and subdivide in their study of par- 

 ticular phases of things that we seem to have 

 a whole host of sciences. To geology belong 

 such sciences as meteorology, geography, 

 paleontology, and mineralogy. Biology di- 

 vides into the two great branches, zoology 

 and botany, and these two branches sub- 

 divide and split up very much like the cells, 

 about which they are so fond of talking, until 

 one is actually lost in their numbers. Rest- 

 ing securely above these, at least so far as 

 complexity of their phenomena is concerned, 

 are the psychologists and sociologists. 



Would an inhabitant of an atom, supposing 

 him to be as small relatively as we are to the 

 earth, find the world about him as complicated 

 and varied as we find ours to be? "Would he 

 require a thousand and one different sciences, 

 of which we do not even dream, in order to 

 interpret what was going on about him and 

 adapt things to his use as we are doing? For- 

 tunately science does not have to answer, for 

 there is no evidence. Science always turns 

 away disdainfully when there is no evidence, 

 and rightly so. It is none of her affair. But 

 the same human being, if he is a scientist, is 

 also a philosopher and a speculator. Perhaps 

 he is a scientist because he is a philosopher and 

 a speculator. At any rate, we can not but be 

 impressed with the richness and luxuriance of 

 our own field of units when we compare it with 

 the poverty with which our mental pictures 



