Photosynthesis1

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E. C. C. BALY, J.B. DAVIES, M. R. JOHNSON, AND H. SHANASSY.—The photosynthesis of naturally occurring compounds. I. The action of ultra - violet light on carbonic acid. When an aqueous solution of carbonic acid in quartz tubes is exposed to ultra-violet light, a photostationary state is established. Ordinary formaldehyde is not a component of this equilibrium, hut there is present an organic compound which is probably a complex aldehyde. Ferrous bicarbonate in aqueous solution is converted by ultra-violet light in the absence of oxygen into ferric hydroxide, organic compounds with reducing properties being simultaneously formed. This reaction appears to take place mainly on the surface of the quartz tubes in which the solution is exposed to the light, and also on the surface of the iron rods used. When an insoluble powder, capable of adsorbing carbonic acid on its surface, such as aluminium powder, barium sulphate, freshly precipitated aluminium hydroxide, or the basic carbonates of aluminium, magnesium, and zinc is suspended in water through which is maintained a stream of carbon dioxide, and the whole is exposed to ultra-violet light, complex organic compounds are photosynthesised. These may be recovered by evaporation of the solution after removal of the insoluble powder. The total quantity of organic compound produced is about 0.02 gm. in two hours when eight quartz test tubes, 9 in. × 1 in., containing in all 720 c.c. of water and the suspended powder, are exposed to the light from a 220-volt U -shaped lamp at an average distance of cm. The organic compoimds thus produced would seem to be of the nature of complex carbohydrates. In the presence of ammonium bicarbonate complex organic compounds are produced which contain nitrogen. Photosynthesis of complex organic material containing nitrogen also takes place when nitrite of potassium or barium is present.