26o SCIENCE PROGRESS 



primitive nature are still apparent, " dextro-rotatory " or " laevo- 

 rotatory," when only one aspect is present, are due to the relative 

 assortment of forces within their molecular structures, properties 

 that do not vary with the physical state of the molecule, so long 

 as the molecular integrity remains, but only vary with the nature 

 of the particular substance. 



When this particular assortment has attained its highest 

 complexity, there is an absence of polariscopic phenomena. 

 That the molecular integrity is also capable of colour pheno- 

 mena is naturally admitted. Here a crystal of copper sulphate 

 absorbs all but the greenish-blue vibration ; if emission were 

 possible without molecular disintegration, it would theoretically 

 emit all vibrations but the greenish-blue ; indeed, we see the 

 momentary evidence of this in the first stages of the emission 

 spectrum of a molecular substance. 



The biological aspect of overtones is even more apparent, and 

 the development of Life, considered in this light, is more readily 

 understood from our views on Immunity, possibly because here 

 they are an aspect of Nature with which we are better acquainted. 



Here it is proved, on very good evidence, that certain sub- 

 stances overproduced by the cells of an organism for its defence 

 — lysins of all sorts — have the same origin and mechanism as 

 certain substances overproduced by the ingestion of foodstuffs 

 into the economy of the cell. It follows, from this and other 

 equally supportive evidence, that a substance ingested either as an 

 unaccustomed food or a poison will, by its degree of toxicity or 

 dissimilarity to the cell, cause the cell to produce a substance to 

 neutralise the harmful effects, and at the same time will cause 

 the cell itself to become so altered in its molecular complexity 

 that these harmful effects are no longer possible. MetchnikofF, 

 in his Theory of Phagocytosis, deals more with the retention 

 of these newly formed substances within the cell that alter 

 its molecular structure than Ehrlich does, who pays more 

 attention to the mechanism of production in his Theory of Im- 

 munity ; but the fact remains that the construction of the cell 

 is altered by moderately adverse nutrition ; and, up to a point, 

 the more gradual and reasonable, for the economic survival of 

 the cell, be the application of the harmful effect, the greater will 

 be the reaction produced by the cell towards its survival. This 

 is essentially the basis of Wright's vaccine treatment : to regu- 

 late the amount of poison administered to the cell, in order to 

 promote its greatest reactive recovery. These curious inter- 

 actions are in every way analogous to our conception of over- 

 tones, only that here the cell itself is altered, and in the case 

 of a more primitive overtone, the fundamental rhythms seem to 

 remain the same : it is probable that the higher in the ladder of 

 complexity be the assortment of force, the more is the effect on 



