38 POPULAR SCIENCE MONTHLY 



ARE THE ELEMENTS TRANSMUTABLE, THE ATOMS 



DIVISIBLE AND FORMS OF MATTER BUT 



MODES OF MOTION? 



By PUOFESSOR S. L. BIGELOW 

 UNIVERSITY OF MICHIGAN 



HMHE advance workers in chemistry and physics are constantly 

 -*- accumulating new facts and propounding new theories which 

 must be digested and incorporated in the body of the sciences. The 

 process of assimilation is often slow, and it is right that new and 

 important facts should be vouched for by more than one investigator, 

 and that a new theory should prove its usefulness before being placed 

 beside old and tried facts and theories. But too often the effects of 

 the advances are unduly delayed through a reluctance to revise old 

 text-books or old lectures, perhaps not so much because of mere laziness, 

 as because of a failure to appreciate the full force of the evidence in 

 favor of new views, or of the advantages to be obtained by their adop- 

 tion. The fact that the arguments for an innovation, for a time at 

 least, are scattered through many journals, leads to an underestimate 

 of their cumulative force. 



It is the purpose of this article to gather the main facts, some old, 

 many recent, most of them fairly generally known, which are com- 

 pelling us to alter our old definitions, and to show what a strong 

 argument they make in favor of believing in the transmutation of the 

 elements, the divisibility of the atoms and that what we call matter is 

 simply a mode of motion. 



It is interesting to note the caution with which text-books express 

 themselves when it is necessary to give definitions for these terms. 

 By a careful choice of words most authors avoid making false state- 

 ments, but they certainly do frequently lead their readers to unjusti- 

 fiable conclusions. For instance, in Roscoe and Schorlemmer's 

 ' Treatise on Chemistry,' issued in 1891, we find the definition, ' An 

 atom is the smallest portion of matter which can enter into a chemical 

 compound.' As is the usual custom, the ideas of the alchemists regard- 

 ing the possibility of transmuting metals is held up to ridicule, and 

 thus, by implication at least, the ultimate nature of the elements and 

 the idea that the atom is indivisible are infallibly conveyed to the reader. 

 A more recent instance is to be found even in the late editions of one 

 of the most widely used texts on general inorganic chemistry. In this 

 book, on page 4, we read, ' Molecules may be defined as the smallest 

 particles of matter which can exist in the free state'; on page 5, 

 ' Atoms are the smallest particles of matter which can take part in a 



