88 Mr Purvis, The absorption spectra, etc. 



(3) It is more probable that the changes may have been 

 produced by the differentiating effect of enzymes, like the 

 oxydases, dissolved from the parsley with the chlorophyll, some 

 of which are known to be very soluble in rectified spirit. In the 

 concentrated solution the enzymes would be in more intimate 

 contact with the chlorophyll than in the dilute solution, and 

 the consequent break down of the chlorophyll molecule would be 

 sooner effected. This suggestion would explain the less general 

 absorption of the strong solution than of the dilute solution after 

 they had been standing for some time, as well as the changes 

 in the appearance and position of the bands, although the 

 substances corresponding to the bands \ 588 and A, 508 do not 

 appear to have suffered much change in the strong solution. 



(4) It is hardly likely that the dissociating force of the 

 solvent was a factor in the changes. The system was too complex 

 to explain them by this theory, for there was not only chlorophjdl 

 in solution, but also, most probably, small quantities of other 

 substances. 



The dissociating effect of the solvent on some dyes may be 

 mentioned in connection with the above-mentioned changes in the 

 chlorophyll solutions. For example, strong aqueous solutions of 

 dyes like eocine and magenta, when diluted in the same way as 

 chlorophyll, gradually and slowly lose their brilliant colour whilst 

 the strong solutions retain it. But the colours of the dilute 

 solutions are at once restored by a single drop of an acid like 

 hydrochloric acid, and there is no such reversion in the dilute 

 chlorophyll solution ; so that the changes produced by dilution of 

 the dyes are not comparable with those of the chlorophyll solutions. 



