1901 - 2 .] Mr J. Fraser on Constitution of Matter and Ether. 27 
no pores within their mass — to account for what passes at present 
as the cause of elasticity. 
To give the reader an idea of this great difficulty I will quote 
from Stallo’s Concepts and Theories of Modern Physics , p. 40, his 
criticism of the various attempts to get over it. Those of my 
readers who are conversant with the subject may skip this part ; I 
quote for the benefit of those who are not. It also lays the subject 
open in a form which I could not hope to do. 
“ Chapter IV. — The Proposition that the Elementary Units of 
Mass are absolutely Hard and Inelastic. 
“ From the essential disparity of mass and motion and the 
simplicity of the elementary units of mass it follows that these 
units are perfectly hard and inelastic. Elasticity involves motion 
of parts, and cannot therefore be an attribute of truly simple atoms. 
“The concept ‘elastic atom,’ justly observes Professor Wittwer, 
‘ is a contradiction in terms, because elasticity presupposes parts, 
the distances between which can be increased and diminished.’ 
“The early founders of the mechanical theory regarded the 
absolute hardness of the component particles of matter as an 
essential feature of the original order of nature. ‘ It seems probable 
to me,’ says Sir Isaac Newton, ‘ that God in the beginning formed 
matter in solid, massy, hard, impenetrable, movable particles, of 
such sizes and figures, and with such other properties and in such 
proportion to space, as most conduced to the end for which He 
formed them ; and that these primitive particles being solids, are 
incomparably harder than any porous bodies compounded of them ; 
even so very hard as never to wear or break in pieces ; no ordinary 
power being able to divide what God Himself made one in the first 
creation.’ 
“Strangely enough, while the requirement by the mechanical 
theory of the absolute rigidity of the elementary units of mass is 
no less imperative than that of their absolute simplicity, it meets 
with an equally signal denial in modern physics ! 
“The most conspicuous among the hypotheses which have been 
devised since the general adoption of the modern theories of heat, 
light, electricity, and magnetism, and the establishment of the 
