184 Prof. B. Moore and Mr. T. A. Webster. 



oxidising action of blue light upon oils, and considers it probable that the 

 effect is due to such an oxidation of the fat-reserve and not a direct action 

 on cell -protoplasm. 



It is highly interesting that the chemical reactions upon substances of 

 biochemical origin, above described, are also produced by the same short 

 wave-lengths as those which occasion death of organisms, as is shown by the 

 enormous decrease in activity when the light is screened by passing through 

 glass or mica. 



Now the substances present in the bodies of the organisms are of those 

 organic types which yield formaldehyde, as shown above, when exposed to 

 the action of light vibrations of the shorter wave-lengths. It is well known 

 that formaldehyde in high dilution is poisonous to such living organisms 

 and when produced nascently by the action of sunlight, or ultra-violet light, 

 and probably at selective concentrations on interfaces, it is quite probable 

 that the death of the whole organism might so be induced. The action of 

 the light would be progressive upon the living cell just as it is within 

 quartz containers upon the more complex organic substances, and would 

 manifest itself in a continuous hydrolysis of the more conjugated to less 

 conjugated substances. The first effect would be upon the state of colloidal 

 aggregation of the system, but concurrently formaldehyde and other organic 

 compounds of simple type would be set free. 



It is noteworthy that formaldehyde and other simple related substances, 

 such as would be the first stages in the evolution of the organic from the 

 inorganic, are all highly poisonous to the much later product in evolution, 

 namely, the living organism. Such simple substances are formaldehyde, 

 formic acid, oxalic acid, hydrocyanic acid, methylic and ethylic alcohols, 

 hydrogen peroxide, and the simpler nitrites and nitriles : all these are 

 poisonous to the highly organised and labile colloids of the bioplasm, and, 

 probably on account of that very property which makes them essential in 

 the first stages of organic evolution, namely, their high reactivity and the 

 ease with which they take part in additive reactions of organic substances. 

 For this reason they must undergo change in any living cell whilst still at 

 high dilution, or else they so interlock into the labile system of organic 

 colloids within the cell as to clog all metabolic change. Hence it is that the 

 energy of light, which is essential to healthy growth and the upbuilding of 

 organic material from inorganic, supplied in a wrong fashion and not shielded 

 in its onset, may reverse these delicate processes and cause death and 

 degeneration of living substance, instead of being the potent agency towards 

 building up fresh material. 



The subject is one of enormous and far-reaching importance. Blue light, 



