IOWA ACADEMY OF SCIENCES. 
141 
GRAPHIC REPRESENTATION OF THE PROPERTIES 
OF THE ELEMENTS. 
BY T. PROCTOR HALL. 
In Mendeleeff’s classification the elements are arranged in 
order on a plane surface, so as to increase along one axis in 
atomic weight, and along the other axis in valence. The prop- 
erties of an element can then, to some extent, be inferred from 
its relation to the others on the diagram. Some of the rela- 
tions are found to be better expressed when the surface is made 
cylindrical. 
Lothar Meyer shows the same properties in a slightly 
different way by placing the elements along one axis at dis- 
tances indicated by their atomic weights, and along the other 
by their atomic volumes. All the known elements then take 
their places on a series of wave- like curves, and similar ele- 
ments have similar positions on the curves. Each curve rep- 
resents one of Mendeleeff’s periods. 
It has been suggested that since in the C. G. S. system 
there are three and only three arbitrary units, namely, mass, 
length and time; a curve might be drawn with reference to 
three coordinates corresponding to the three fundamental 
units, and that the positions of the elements on such a curve 
ought to be a complete expression of their properties. But if 
we take only two arbitrary units, say mass and length, all 
others may, as is well known, be derived from them. In grav- 
itation, force is related directly to mass-and inversely to length. 
Acceleration varies as force, and the unit of time may be easily 
defined in terms of acceleration and length. But it does not 
follow that the properties of the elements can be well expressed 
by a two -fold diagram. Elements and atoms are solids and 
exist in three-fold space. The constant relation of mass to 
gravitational force makes it highly probable that all the atoms 
are composed of the same basal matter, and that their differ- 
ences arise from differences in atomic structure, and in the 
