572 TEE POPULAR SCIENCE MONTHLY 



losing electrons and, therefore, atomic weight, until, a certain critical 

 point being reached, a readjustment takes place resulting in transmuta- 

 tion to a lower element, it may be supposed that the atomic weights of 

 the elements may vary in different worlds of space. The more or less 

 uniform weights found on this planet would be due to the fact that the 

 period of formation was practically identical in all cases. The slight 

 divergences between the theoretical and actual atomic weights in the 

 periodic system would be due to the electron contents having fallen 

 below the contents at the last points of readjustment. The list of the 

 chemical elements arranged in decreasing order of their atomic weights 

 would represent the steps of the degradation from the highest elements 

 having, possibly, atomic weights exceeding 250. It was further sug- 

 gested that the atomic weights of the elements in meteorites be deter- 

 mined to check the truth of the theory of transmutation by disintegra- 

 tion ; as far as known this has not yet been attempted. 



It would seem to be rather idle to discuss the possible reasons for 

 the diversity of elements in each chemical group on the assumption that 

 they all originated at one time for each individual body in space from 

 extremely dense elements, themselves concentrates of the one primal 

 element. At most, it is proper to state the theory as follows. As the 

 nucleus of a nebula condenses and cools into a solid mass, the structure 

 of the matter at the center becomes extremely dense and the atomic 

 weights are high ; these weights taper off to the surface, which is then of 

 a somewhat irregular and slag-like nature like the crust of the earth 

 and brings to mind many parallel cases in metallurgy. Many scientists 

 hold that the earth has solidified more or less in the shape of a modified 

 tetrahedron; if this be true, it encourages the view of a fairly homo- 

 geneous core which may be composed of elements even heavier than 

 radium, thorium and uranium. The radioactive properties of these 

 elements may account for the internal heat of the earth. The view that 

 the bulk of this globe of ours is of similar composition to the crust is 

 not only unjustifiable, but highly improbable; the slag of a steel-making 

 process is a good indication of what there is not underneath. The 

 theory of a core composed of elements having high atomic weights will 

 go far to explain the high average density of the earth as compared with 

 that of the crust. 



The Electrical Nature of Gravitation 

 A discovery of inestimable value is due to Kaufmann ; he found that 

 the mass of the a particle varied with the velocity. This discovery all 

 but consecrated the old theory that mass, that gravitation, is a form of 

 energy, a mode of motion. There can not be a manifestation of energy 

 when the motion is uniform. No motion of energy can be evidenced 

 without acceleration followed by arrest and a reversal of motion, or 



