EVIDENCE OF INORGANIC EVOLUTION 



583 



THE EVIDENCE OF INORGANIC EVOLUTION 



By SIDNEY LIEBOVITZ 



WHEN we consider the marked resemblances and striking inter- 

 relations of the elements as expressed by the Periodic System, 

 the conviction grows more and more strongly upon us that this system 

 is the external expression of a fundamental process in nature, to which 

 are due the general properties, as well as the individual characteristics, 

 of the elements. On the present occasion I shall endeavor to point out 

 that between the Periodic classification and the ordinary zoological 

 classification, such analogies exist as tend to indicate an identity in 

 fundamental principle. We shall then consider some of the phenomena 

 which are at the foundation of the law of organic evolution, and here, 

 too, we shall find among the elements conditions exactly corresponding. 



A Family of the Elements Compared with a Homologous Series 



Before proceeding farther, however, it is of interest to note the simi- 

 larities which exist between a family of the elements and a homologous 

 series of organic compounds. For the purpose of this comparison it is 

 most useful to select the homologous series of fatty acids, C„H 2n+1 C00H. 

 If we should arrange the normal acids of this series in order of molec- 

 ular weight, we should find that between such a series and a family of 

 the elements there exist certain close analogies, which are tabulated 

 below in parallel columns. 



Fatty Acids (CnH^^COOH) 



1. There is a constant difference in 

 molecular weight between consecutive 

 members of 14, due to the constant 

 group difference CH 2 . 



2. The first member of the series, 

 formic acid, differs somewhat in 

 properties from the other members 

 of this homologous series. Thus, it 

 manifests the characteristics of an 

 aldehyde, reducing ammoniacal solu- 

 tions of silver nitrate, etc. It has no 

 corresponding chloride or anhydride, 

 is readily decomposed into CO and 

 H 2 0, etc. 



Family of the Elements 



1. There is a fairly constant differ- 

 ence in atomic weight between con- 

 secutive elements of the same family 

 of about 45, except between the first 

 and second (and in some cases be- 

 tween the second and third), where it 

 is about 16. 



2. The first member in each family 

 of the elements differs somewhat from 

 the other members. Thus, lithium dif- 

 fers from the other elements of its 

 family in forming an almost insoluble 

 carbonate and phosphate. Oxygen, 

 again, differs from sulphur, selenium 

 and tellurium in that its hydride is a 

 colorless and odorless liquid, while 

 those of the others are gases of dis- 

 agreeable odor; in that it is seldom, 

 if ever, more than divalent; in being 

 gaseous under ordinary conditions of 

 temperature and pressure, etc. 



