Action of Light Rays 07i Organic Compounds, 171 



was exposed during a whole week of bright sunshine in June, 1915, on the 

 laboratory roof, being contained in a quartz test-tube. It was then distilled 

 and tested with negative results. 



These experiments clearly show that an inorganic energy-transformer is 

 necessary, and that carbon dioxide alone in aqueous solution in sunlight does 

 not form formaldehyde; secondly, that the formaldehyde is not a decom- 

 position product of traces of more highly organised substances, but is actually 

 built up by the inorganic colloid absorbing the energy of the sunlight and 

 so becoming activated and reacting on the water and carbon dioxide, trans- 

 ferring the energy and producing formaldehyde. 



Both the elements hitherto described, viz., uranium and iron, form higher 

 and lower oxides, and it might, therefore, be urged that the higher oxide 

 became reduced by the energy of the sunlight to a lower oxide with greater 

 energy content, and that this lower oxide parting with its acquired energy 

 to the water and carbon dioxide formed the formaldehyde to which the 

 energy of the sunlight was thus indirectly transferred. Such a view is of 

 interest because similar changes do actually occur in certain life processes, 

 where various types of micro-organism, such as iron organisms, sulphur 

 organisms, and nitrogen-assimilating or carbophilous organisms carry out 

 similar energy transformations. The so-called iron bacteria are capable in 

 darkness, as within an iron water-cistern or water-main, of utilising the 

 energy of metallic iron or ferrous oxide, when given out in the process of 

 oxidation to the ferric condition. The organism is enabled by a linked, 

 reaction to utilise for building up from carbon dioxide and water those 

 reduced organic substances which form its body material. Similarly, the 

 philothionic organisms are capable of utilising the energy of sulphur, or 

 reduced sulphur compounds, to build up organic carbon compounds, and the 

 nitrogen-assimilating organisms fed with organic carbon compounds can link 

 up to the endothermic reactions necessary to convert the atmospheric 

 nitrogen into ammonium salts or nitrites, and from these build up proteins. 



In all cases where the energy of light is absent, however, there must 

 evidently have been previously a light-transforming reaction at some earlier 

 period of history, for without this the metal or lower oxides, or sulphur or 

 sulphide would never have been formed upon which the organism not 

 utilising light depends for its store of energy. In a world cooling down 

 from red-heat, in presence of free oxygen in its atmosphere, all these sub- 

 stances would have been completely oxidised, and so the immense world 

 deposits of pyrites and ferrous oxide and such-like reduced substances, just 

 like coal, shale and petrol, must have originated from previous life pro- 

 cesses, accompanied by energy transformations in presence of sunlight. 



