# Page:Popular Science Monthly Volume 56.djvu/736

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POPULAR SCIENCE MONTHLY.

In short, for the formation of our starch the water (H2O) from the soil and the CO2 of the atmosphere, when brought together, may be made to combine with the formation of starch. A single diagram, while not perhaps an absolute statement of fact, may serve to represent the final result:

 ${\displaystyle \scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}}$ 6CO25H2O = C6H10O5 + 12O.

In other words, the six molecules of carbon dioxide and five of water combine with the formation of one molecule of starch and the liberation of twelve atoms of oxygen.

This driving off of such a large amount of oxygen, entirely against the whole tendency of that element, it is assumed, is at the expenditure of much force. The only one adequate to this work is solar energy, and this is abundantly at hand. That we need not seek further for this power is proved by many and conclusive tests. Vegetable physiologists to-day are able not only to locate the sun as the chemist, that effects the changes necessary for the production

Fig. 5.—Diagrammatic View of the Process of Photo-Synthesis.

of starch, but can show in what cells and portions of those cells the forces effect the synthesis. The chlorophyll granules in the living cell are the microscopic laboratories in which a silent chemist, powerful beyond all measurements, builds out of inorganic materials the food substance of the whole world of animals and plants.