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science have surely possessed that quality of mind which philosophy would most 
approve. If, as has often been remarked, Faraday was mathematically-minded, 
though untraived in mathematics, it seems not less true that he stood in the same 
relation to philosophy. When, for example, he was asked to express his opinions 
on the atomic theory, he wrote as follows :— 
‘T do not know that 1 am unorthodox as respects the atomic hypothesis. I 
believe in matter and its atoms as freely as most people—at least I think so, As 
to the little solid particles, which are by some supposed to exist independent of 
the forces of matter, and which in different substances are imagined to have 
different amounts of these forces associated with, or conferred upon, them (and 
which even in the same substance, when in the solid, liquid, and gaseous state, 
are supposed to have like different proportions of these powers), as I cannot form 
any idea of them apart from the forces, so I neither admit nor deny them. They 
do not afford me the least help in my endeavour to form an idea of a particle of 
matter. On the contrary, they greatly embarrass me; for after taking account of 
all the properties of matter, and allowing in my consideration for them, then 
these nuclei remain on the mind, and I cannot tell what to do with them. The 
notion of a solid nucleus without properties is a natural figure or stepping-stone 
to the mind at its first entrance on the consideration of natural phenomena; but 
when it has become instructed, the like notion of a solid nucleus, apart from the 
repulsion, which gives our only notion of solidity, or the gravity, which gives our 
notion of weight, is to me too difficult for comprehension; and so the notion 
becomes to me hypothetical, and, what is more, a very clumsy hypothesis. At 
that point, then, I reserve my mind as I feel bound to do in hundreds of other 
cases in natural knowledge.’ 
This is the attitude of mind, I think, of all thoughtful chemists ; if they do 
not exhibit it ostentatiously it is only because it is as disturbing to the proper 
work of a chemist for him to be constantly dwelling on the inward nature of his 
hypotheses as it is distracting in ordinary life to have men always talking about 
their emotions. 
Few, I think, will deny that the atomic theory stands to-day as an indispensable 
instrument for productive chemical work ; it has neither had its day nor ceased 
to be. Physicists have never been quite satisfied with the hard, indivisible ball of 
specific substance and definite mass which has served chemistry so well. They 
have given it bells, have made a vortex ring of it,and have indeed done much that 
few chemists can understand to make it meet the exacting requirements of their 
science. But to us it has always been the same; what we have done to it has 
been external; we have given it, vaguely perhaps, a charge of electricity, a store 
of energy; we have attached the hooks or rods of valency, but we have not 
meddled with its interior. We are now called upon by chemical considerations of 
change of composition, as well as by other considerations more recondite, to 
subdivide our atom, to credit it with an unsuspected store of energy, to consider 
it a congeries of unsubstantial electrons. We should wish, of course, to know that 
the evidence is good enough, but otherwise there can be no possible objection from 
our side; it will undo nothing that has been done, and we may have good hopes 
that it will lead to the doing of many new things in chemistry. The newer 
theories are in consonance with the old in one most vital point: they afford those 
mental pictures of phenomena which most of us find indispensable for fruitful 
work, They do not belong to what Professor Schaster has characterised as ‘ the 
evasive school of philosophy.’ ‘ ‘Those,’ he says, ‘ who believe in the possibility of 
a mechanical conception of the universe, and are not willing to abandon the 
methods which from the time of Galileo and Newton have uniformly and exclu- 
sively led to success, must look with the gravest concern on a growing school of 
scientific thought which rests content with equations correctly representing 
numerical relationships between different phenomena, even though no precise 
meaning can be attached to the symbols used.’ Most of us, I think, will take 
comfort in this pronouncement and rejoice that if our conception of the atom is 
to be transformed, it may still be represented as having some kinship with what 
Sir Henry Roscoe’s famous examinee described as the ‘square blocks of wood 
invented by Dr. Dalton,’ 
