158 ILLINOIS STATE ACADEMY OF SCIENCE 



transparent. In the same way Schonben explained the 

 fresh penetrating odor noticeable after an electric storm, 

 by passing an electric spark through oxygen and identi- 

 fying the same odor. 



Although our classification is entirely justifiable we 

 must remember that nature has no such scheme in mind 

 when she provides her phenomena, and consequently 

 most of them do not fit conveniently into our water tight 

 compartments. We have a good example of this in 

 osmosis. Its character and explanation is physical, but 

 its importance comes in chemistry, as a proof of ioniza- 

 tion, and in biology where it explains the rise of liquids 

 in the roots of plants and trees. 



It is because our classification is more artificial than 

 natural that we are constantly finding relations between 

 the sciences. Each science depends upon the others, and 

 examples of this interdependence are numerous. 



The fundamental conceptions of chemistry are physi- 

 cal in character as well as in the method of arriving at 

 them. The atomic theory is undeniably physical, but, 

 at the same time it is true that its proof is based on con- 

 tributions from both sciences. Historically, the chemical 

 law of combining weights was a strong factor influencing 

 its adoption, but recently the objective reality of the 

 atom has been established by calculation of its mass and 

 dimensions from data obtained from radium emanation. 

 The close approximation between results obtained in this 

 way and those from more indirect methods is the phys- 

 icist's proof of the atomic theory. 



Other chemical conceptions are greatly enriched by 

 considering them in the light of sub-atomic physics. Oxi- 

 dation in chemistry originally was a narrow and re- 

 stricted term which included only the addition of oxy- 

 gen to metals. If oxidation is kept entirely within the 

 field of chemistry, there is little possibility of broaden- 

 ing its meaning. It is true that it may be defined as the 

 increase of positive valence, but where these valences 

 come from is a problem of the physical chemist. We 

 now define oxidation as the loss of electrons with the 

 result that not only has the scope of the term been en- 

 larged but the very nature of its mechanism has been 



