686 TKANSACTIONS OF SECTION I. 



probably not be going too far to say that the peculiarities of the phenomena 

 called ' vital ' are due to the fact that they are manifeetations of interchange 

 of energy between the phases of heterogeneous systems. It was Clerk Maxwell 

 who compared the transactions of the material universe to mercantile operations 

 in which so much credit is transferred from one place to another, energy being 

 the .representative of credit. There are many indications that it is just in this 

 process of change of energy from one form to another that special degrees of 

 activity are to be observed. Such, for example, are the electrical phenomena 

 seen in the oxidation of phosphorus or benzaldehyde, and it appears that, in the 

 photo-chemical system of the green plant, radiant energy is caught on the way, 

 as it were, to its degradation to heat, and utilised for chemical work. In a 

 somewhat similar way, it might be said that money in the process of transfer is 

 more readily diverted, although perhaps not always to such good purpose as in 

 the chloroplast. Again, just as in commerce money that is unemployed is of no 

 value, so it is in physiology. Life is incessant change or transfer of energy, and 

 a system in statical equilibrium is dead. 



The following Reports and Papers were then read :- 

 1. Repnrt on AncBsthciica. 



2. Report on Eleclrojnotivc Phenomenain Planta. — SeeEeports, p. 218. 



3. Report on the Structure and Fvnction of the Mavrmalian Heart. 



4. Report on the Dnetle.'is GlancU. — See Eeports, p. 217. 



5. The Action of Light on certain Inorganic and Organic SiihRtance!^. 

 By Professor Benjamin Moore, F.R.S. 



6. Some Fundamental Fads of Vision and. Colour Vision. 

 By P. W. Edridge-Green, M.D., F.R.C.S. 



There are two assumptions, neither of which has any foundation in fact, 

 which have made the interpretation of the facts of vision and colour vision very 

 difficult if not impossible. These two assumptions are that the rods are 

 percipient elements, and that there are definite specific fundamental sensations 

 which by their mixture give rise to other sensations. The facts of vision and 

 colour vision are directly opposed to both of these assumptions. There is no 

 qualitative difference between the foveal region, in which only cones are present, 

 and the para-foveal region, in which there are both rods and cones. The fact 

 that the positive after-image can change its relative place in the field of vision 

 whilst the eye remains unmoved shows that the photo-chemical stimulus must be 

 outside the cones. It is difficult to imagine the photo-chemical substance 

 situated in the cones, as how would this be regenerated, seeing there is no 

 direct blood supply to the cones? 



The assumption that there are fundamental colour sensations which by their 

 mixture give rise to other colour sensations has also no foundation in fact. 

 This assumption has made the fact that a colour-blind man can pass the wool 

 te.st (as about 52 per cent, of dangerous cases can) unintelligible. 



Recent writers who have endeavoured to explain the fact have tried to 

 account for it on a so-called colour-blindness of the fovea. It is, however, 

 quite easy to show that the colour-blindness is not limited to the fovea. A man 

 whom I designate a trichromic will in favourable conditions make matches 



