ELISHA MITCHE1,.L SCIENTIFIC SOCIETY 5 
The insight into what Lucretius would call ‘the nature of 
things’ was becoming clearer; the mental grasp upon these 
elusive atoms about which the old Epicurean reasoned so 
shrewdly was becoming firmer. Through what one must re- 
gard as the veil interposed by the earlier idea of the element, 
the chemist began to grope after the constituent particle or 
atom. It must be borne in mind that the definition of the 
element was largely formulated before the resuscitation of the 
atomic theory by Dalton, and the mental picture of the one 
has perhaps retarded the clearing up of the ideas concerning 
the other. From the atomic point of view the element was 
next defined as one in which the molecules or divisible particles 
were made up of similar indivisible particles. This afforded 
an easy explanation of allotropism as achange in the num- 
ber of atoms in a molecule. As Remsen says: ‘‘An element 
is a substance made up of atoms of the same kind; a com- 
pound is a substance made up of atoms of unlike kind,” 
Laying aside, then, all vaguely formulated ideas of essen- 
ces, or principles, or simple bodies, or elemental forms, we 
found our present building upon the conception of the ulti- 
mate particle, be this molecule or atom. 
As to this atom some clear conception is needed, and here 
we come to the crux of the modern theories. The chemist re- 
gards this atom as a particle of matter and is unwilling to ac- 
cept the theory of Boscovich that is infinitely small, and 
hence a mathematical point,nor can he admit that it is mere- 
ly a resisting point, and hence that all matter is but a system 
of forces. And yet it seems as though some authorities 
would lead up to such a conclusion. 
While we need not consider these atoms as mere centers of 
forces, we are compelled to study them by the operation of 
forces upon them. What are called their properties have 
been studied and recorded with great care. These proper- 
ties are evinced in the action of the forces upon matter, and 
the exhibition of force without matter cannot be admitted. 
This study of the properties has been the especial occupation 
of the century now closing, and so the elemental atom has 
come to be regarded as a collection of properties. As Pat- 
terson-Muir puts it (Alchemical Essence and the Chemical 
