ON THE STRUCTURE OF ATOMS. 



Chemists are now quite generally disposed to admit that the 

 original and ultimate form of all matter is some single simple 

 substance, and that what we call the atoms or simple elements, 

 numbering now about sixty-five, are only different manifestations 

 of this universal matter, depending on the quantity combined 

 and the degree or complexity of its condensation. This theory 

 accords so well with the first principles of chemical science, and 

 with the tendency of all inductive knowledge, which is to bring 

 facts and particular phenomena under more simple and general 

 laws and conditions, that there is scarcely a writer on chemistry 

 who has not somewhere shown a leaning toward this greatest of 

 all generalizations the unification of matter. 



This field of inquiry is the great border land between the 

 known and the unknown. As such, it has been so long the 

 batting ground of the metaphysicians, that one feels almost like 

 offering an apology for attempting to introduce a little common 

 sense, or at least common language, into it. Still I have the 

 courage to think that some clear reasoning may be held and some 

 pertinent facts presented looking towards this great simplifica- 

 tion. I will at least attempt to find how far we can go in 

 this direction without abstruse speculation. 



It is a well known principle of chemistry that all true gases, 

 under the same quantity of heat and pressure, have precisely the 

 same number of molecules or ultimate particles in the same vol- 

 ume. A cubic foot of oxygen or hydrogen or carbonic acid or 

 any other gas contains in each case exactly the same number of 

 atoms or molecules. Therefore the weights of the cubic feet of 

 all the gases will correspond to the weights of their molecules. 



