October i, 190S] 



NA TURE 



553 



of the dead was found, and disposal of the body once for 

 all ; in the north and east the flesh was removed from 

 the bones, and only with the burial of the latter was 

 the spirit supposed to be dismissed to its own place; in 

 thi- Miulh the grave was the abode of the spirit. 



Mr. W. W. Skeat's paper dealt with traces of totemism 

 in the .Malay Peninsula ; totemism implies a group name, 

 a belief in group kinship, and respect for " the blood," 

 and of these the second is the primary one from which 

 the others have sprung; but he was inclined to hold the 

 view that totemism was originally independent of the notion 

 of kinship ; the Semang have not, as contended by Mr. 

 Gomme, plant totemism, for plant names are far from 

 general. 



Among other papers may be mentioned one by Mr. Hollis 

 on the Nandi, which suggests that their religion is a cross 

 between Bantu ancestor cult and the Masai sky-god cult. 



The social side of the congress was well looked after, 

 and receptions were given by Prof. Gardner and Dr. Evans 

 at the Ashmolean, Mr. Mar'rett and Dr. Farnell at Exeter, 

 Profs. Driver and Sanday at Christ Church, Prof. Carpenter 

 at Manchester College, and by the Mayor and Mayoress. 



THE BRITISH ASSOCIATION. 



SECTION I. 



PHYSIOLOGY. 



Opening .Address by J. S. Hald.\ne, M.D., F.R.S., Fellow 

 OF New College .^nd Re.ader in Physiology in the 



U.NIVERSITY of OXFORD, PRESIDENT OF THE SECTION. 



The Relation of Pliysiology to Physics an<l Chemistry. 



In choosing to address you on the relation of Physiology 

 to Physics and Chemistry, I am aware that I have selected 

 a subject which has already been treated from this chair 

 by more than one distinguished predecessor. My excuse 

 for returning to it again is that it not only possesses deep 

 scientific interest for us all, but that a great deal remains 

 to be said about it. 



The majority of physiologists in recent times have ex- 

 pressed more or less clearly the opinion that Physiology is 

 the application to living organisms of the methods and 

 modes of explanation of Physics and Chemistry. It is, in 

 short, Phvsics and Chemistry applied to the activities of 

 living organisms ; so that the only explanations aimed at 

 in Physiology are, or ought to be, physical and chemical 

 explanations. A minority, which is at present a growing 

 one, I think, have either definitely dissented from this 

 view, or have remained unconvinced of its truth. .As one 

 of this minority I should like to place before you as shortly 

 as possible what seem to me to be the main reasons of 

 our dissent. Let me add that I have carefully pondered 

 over these reasons during many years of active physiological 

 work. 



When we look back on the history of Physiology is seems 

 perfectly evident that physiological progress has been 

 dependent on the progress of Physics and Chemistry. On 

 this point there is no room for doubt. To take only one 

 example, where should we be in the investigation of 

 animal metabolism but for the ideas and experimental 

 methods furnished to us by Physics and Chemistry ? Wc 

 should know next to nothing about respiration, animal heat, 

 nutrition, or muscular and other work. Physiology depends 

 at every turn on Physics and Chemistry, and its future 

 progress will certainly be equally dependent on advances in 

 phvsical and chemical knowledge. This consideration has, 

 I imagine, weighed very heavily in the minds of those 

 physiologists who have concluded that Physiology is nothing 

 but applied Physics and Chemistry. A further fact which 

 weighs equally heavily is that in spite of diligent search 

 no fact contradicting the fundamental laws of conservation 

 of matter and energy has been discovered in connection with 

 living organisms. 



When, however, we ask what progress has been made 

 towards the physico-chemical explanation of physiological 

 processes, we at once enter upon controversy. We may 

 point to advances in some directions, but they are accom- 

 panied by the appearance of unforeseen difficulties in other 

 directi'ons. Again, to take animal metabolism as a typical 



NO. 2031, VOL. 78] 



instance, the investigations of the last hundred and twenty 

 vcars have enabled us to assign ultimate physical and 

 chemical sources to the energy and material leaving the 

 body in various forms. We can assign to such sources the 

 energy of animal heat, muscular work, glandular, nervous, 

 and other activity : also the carbon dioxide, urea, salts, 

 and many other substances which leave the body or are 

 formed within it. .All of this new knowledge may be' 

 regarded as progress towards a physico-chemical explanation 

 of life. 



But there is another aspect to be considered ; for side 

 by side with what I have just referred to there has been 

 a different kind of increase of knowledge with regard to 

 animal metabolism. This growth of knowledge relates tO' 

 the manner in which the passage of energy and material 

 through the body is regulated in accordance with what is 

 required for the maintenance of the normal structure and 

 activities of the body. In Liebig's time, for instance, it 

 was believed that the rate of respiratory exchange was- 

 regulated simply by the supply to the body of oxygen and 

 food-material. If one breathed faster, or if the barometric 

 pressure or percentage of oxygen in the air increased, the 

 respiratory exchange was assumed to be also increased, 

 just as ordinary combustion outside the body would be- 

 increased by an increased supply of oxygen. If, again, one 

 took in more food it was supposed that the excess went 

 to increase the rate of combustion in the blood (luxus con- 

 sumption), just as a fire is increased when more fuel is 

 supplied. W'e now know that these assumptions were 

 wholly mistaken, and that the respiratory movements, 

 respiratory exchange, and corresponding consumption of food 

 material in the body are regulated with astounding exacti- 

 tude in accordance with bodily requirements. If, for 

 instance, the body consumes more proteid, it economises 

 a quantity of fat or carbohydrate equivalent in energy value 

 to the proteid ; and from day to day the amount of energy 

 liberated in the body is very steady. With regard to the 

 excretion of material by the kidneys a similar growth in 

 knowledge can be traced. It is scarcely a century since 

 the urine was regarded as equivalent more or less to the 

 liquid part of the blood separated from the corpuscles, 

 which were unable to pass through the very fine capillary 

 tubules supposed to exist in the kidney substance. 

 Gradually, however, we have learnt how extraordinarily 

 delicate is the selective action which occurs in the kidney 

 substance, and how efficiently this selective action maintains 

 the normal composition of the blood. Scarcely a remnant 

 is now left of the old filtration theories. Our ideas of 

 tissue nutrition and growth have undergone a similar 

 change ; and it is hard to realise that only about seventy 

 years^ ago Schwann could put forward the theory that cell 

 formation and growth is a process of crystallisation. 



One can multiply instances like these almost indefinitely ; 

 but I have, perhaps, said enough to show that if in some 

 ways the advance of Physiology seems to have taken us 

 nearer to a physico-chemical explanation of life, in other 

 ways it seems to have taken us further away. On the one 

 hand we have accumulating knowledge as to the physical 

 and chemical sources and the ultimate destiny of the 

 material and energy passing through the body ; on the other 

 hand an equally "rapidly accumulating knowledge of an 

 apparent Ideological ordering of this material and energy ; 

 and for this teleological ordering we are at a loss for 

 physico-chemical explanations. There was a time, about 

 fifty years ago. when the rising generation of physiologists 

 in "their enthusiasm for the first kind of knowledge closed 

 their eves to the second. That time is past, and we must 

 once more face the old problem of life. 



Let us first look at the answer given to this problem by 

 many of the older physiologists. Roughly speaking, they 

 carried phvsical and chemical explanation of physiological 

 processes as far as they could, and for the rest assumed 

 that at some point or other the physical and chemical 

 factors are interfered with and ordered in a teleological 

 direction bv something peculiar to living organisms — the 

 "vital principle" or "vital force." This theory, if one 

 can call it a theory, had the negative merit that it did not 

 lead physiologists to ignore facts which they could not 

 explain.' But in practice the " vital force " became simply 

 a convenient resting-place for these facts. It was assumed 

 that the vital force could do anything and everything, and 



