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Rh ascertained that a fully satisfactory theory can be established in regard to diverse activities of life; it is not improbable that these will some day be ultimately traced to physico-chemical reactions.

Physics in a larger sense includes investigations on the reactions of matter, both inorganic and living. The methods of investigation are identical in two cases. The various appliances described, the very high magnification and record of imperceptible movements, the automatic record of extremely short intervals of time and the rate of reaction, the measurement of energy of different rays of the solar spectrum and of the transformation and storage of the energy by the photosynthetic organ—these and others will also be found of value in the advancement of purely physical and physico-chemical investigations.