FORMALDEHYDE FORMATION IN THE PHOTO-OXIDATION OF ORGANIC COMPOUNDS AND THE FORMAL DEHYDE THEORY OF CARBON ASSIMILATION.

It has been observed that formaldehyde is produced during the photo-oxidation of organic compounds such as, glycine, citric acid, acetic add, oxalic acid, canesugar etc.

On the basis of the amount of formaldehyde formed during photo-oxidation, all the organic substances investigated by the authors have been divided into three groups :—

(a) Formaldehyde obtained as a direct product of photo-oxidation such as, glycine, acetic add, methyl violet etc .

(b) Formaldehyde obtained may be partly due to the direct photo-oxidation of the substance and partly due to its photosynthesis from carbon dioxide generated 'during oxidation.

(c) Formaldehyde detected may be due to its photosynthesis from energy-rich carbon dioxide produced during photo-oxidation.

The production of formaldehyde is not only limited to substances of biochemical origin as observed by Moore, Wager etc, but it can be detected during the photo-Oxida­tion of any organic substances provided it can be oxidised to carbon dioxide and water in light.

It is easier to obtain formaldehyde from carbon dioxide generated during the photo-oxidation from organic compounds than from potassium bicarbonate solutions or carbon dioxide solution because the former is associated with energy evolved during oxidation.

The energy produced during respiration is concluded to supply a part of the energy need for photosynthesis.

Besides light, carbon dioxide, moisture and chlorophyll, energy from respiration seems also necessary for photosynthesis.