Note 129 — Chapter VII · MODERN ALCHEMY

For a defence of the view that chemical substances may be regarded as energy-complexes, and that this view is equally as valid as the older notion of a chemical substance as an inertia-complex, i.e., as something made up entirely of different units or atoms each characterised by the possession of a definite and constant weight at a fixed point on the earth’s surface, see an article by the present writer, entitled “The Claims of Thermochemistry,” Knowledge and Scientific News, vol. vii. (New Series), pp. 227 et seq. (July, 1910).

[130] In some cases the heat change accompanying the transformation of an element into an “allotropic modification” can be measured directly. More frequently, however, it is calculated as the difference between the quantities of heat obtained when the two “forms” are converted into one and the same compound.