August 23, 1906] 



NA TURE 



425 



years before these are completed, but the introduction of 

 vitalism or biotic energy as a fictitious causative explan- 

 ation is so opposed to the spirit and the progress of science 

 that we may safely predict the complete abandonment of 

 this position at a comparatively early date. 



I venture now to define my own position in regard to 

 this matter. I assert that, although the complexity of 

 living tissues makes our present knowledge extremely 

 limited, it is essentially unscientific to say that any physio- 

 logical phenomenon is caused by vital force or is an argu- 

 ment in favour of " vitalism," and that, if this phraseology 

 is offered as a sufficient description of the phenomenon, 

 its further scientific study Is prejudiced because the only 

 terminology which admits of scientific exactitude is 

 excluded. I assert, further, that if the term " vitalism " 

 connotes no more in physiology than the term "living," 

 its employment does not in any way enlarge our intellectual 

 view' of the subject-matter of physiology, and can only 

 be considered either as meaningless tautology or as an 

 expression of faith ; but if the term has some additional, 

 occult, and mystic significance, then its employment is 

 detrimental to the progress of physiology, exerting as 

 obstructive an influence upon the growth of our science 

 as the conception of special creation exerted upon the 

 progress of biology. 



Vitalism is not the only " ism " which, perhaps un- 

 wittingly, obstructs physiological progress ; it is, however, 

 far more worthy of respect than others which I do not 

 propose to particularise, for it is a twig of that lusty tree 

 which, in philosophy, still claims the largest share of 

 men's belief. The vitalist, leaving the more solid ground 

 of physics and chemistry, enters the realm of metaphysics 

 and there attaches himself to that distinguished circle of 

 idealists whose pedigree extends back to Plato. If, as 

 may be asserted with great confidence, idealism in philo- 

 sophy will endure as long as thought exists, then it might 

 be expected that vitalism in physiology will never entirely 

 cease. The history of physiology, however, reveals the 

 fluctuating extent of its influence. Potent a century or 

 more ago, vitalism nearly disappeared between 1S50 and 

 1S70 under the pressure of the application of phvsical and 

 chemical methods to physiology ; it revived again towards 

 the century's close, the ripple of a wide-spreading wave 

 of idealistic philosophy. Materialism and idealism have 

 been described by Huxley as appearing in the history of 

 philosophy like " the shades of -Scandinavian heroes 

 eternally slaying one another and eternally coming to life 

 again." As a physiologist, I do not venture to touch 

 however lightly upon this metaphysical duel, since I frankly 

 admit my own incapacity to do so and the particular 

 applicability to my own powers of the words of Gibbon 

 that " it is much easier to ascertain the appetites of a 

 quadruped than the speculations of a philosopher." It is 

 therefore without any intention of casting anv suspicion 

 of doubt upon the confidence felt as to the persistence of 

 idealism in philosophy that I suggest that neo-vitalism 

 in physiology bears upon its surface the signs of its own 

 decay. One such sign is the circumstance that even its 

 most ardent exponents refuse to follow the lead of this 

 loin's fatiius, but assiduously investigate living processes 

 by the most improved chemical and physical methods ; 

 another is that w*en any so-called vitalistic aspect of some 

 physiological phenomenon is rendered explicable on phvsical 

 and chemical lines, the vitalist abandons in this instance 

 his peculiar standpoint. Neo-vitalism has of late thus lost 

 its corrosive character; it now spreads as a thin but 

 tenacious film over physiological conceptions and is in this 

 way mildly obstructive, but its obstructive viscosity is con- 

 tinually yielding to the accumulating mass of the more 

 precise knowledge which it endeavours to obscure. Re- 

 search along physical and chemical lines into physiological 

 processes is its uncompromising opponent, so that there is 

 every reason for believing with Huxlev that the weight 

 and increasing number of those who refuse to be the prey 

 of verbal mystifications have begun to tell. 



The recent history of physiological progress shows that 

 investigations confined to the study of physical and chemical 

 processes have been the one fruitful source of physiological 

 knowledge. It would be impossible to give even a brief 

 survey of the chief results which have, during the last 

 twenty years, been thus obtained. Out of the enormous 



NO. 1 92 I, VOL. 74] 



wealth of material I select one of great importance and 

 promise. It is that of the constitution of the nitrogenous 

 compound familiarly known as proteid, which from its 

 clo.se association with protoplasm, the physical basis of life, 

 has a fundamental significance and has therefore attracted 

 the attention of inany competent investigators. Important 

 researches have been made on this subject by physiological 

 chemists, notably Ilofmeisler and Kossel, and at the pre- 

 sent time the subject is also being studied by one of the 

 ablest organic cheinists of the day, Emil Tlscher, whose 

 previous work on carbohydrates is so illuminating.' In 

 the splendid chemical laboratory at Berlin, with Its un- 

 paralleled equipment, a succession of researches have been 

 carried out dealing not only with the constitution of the 

 siiTipler proteid derivatives, but also with the important 

 and difficult problem of the synthetic grouping of these 

 derivatives into more complex compounds. The success 

 which has so far attended these investigations is so pro- 

 nounced as to encourage the hope that the future may 

 reveal the chemical constitution of proteid itself and thus 

 bring us perceptibly nearer to its possible synthetic form- 

 ation. We congratulate ourselves that this problem has at 

 last attracted the earnest attention of organic chemists. 



I now invite your attention to those further aspects 

 Indicated in the opening sentence of this address, which 

 imply the presence of automatic inechanisms by which the 

 various processes of the body organs are regulated and 

 coordinated for the welfare of the whole organism. 



Many such automatic mechanisms are now known. 

 Some of these are of an obvious chemical type, the 

 mechanism being the production in minute quantity of 

 chemical substances which are conveyed to remote organs 

 bv the circulating blood. In this way adrenalin, a sub- 

 stance elaborated by the medullary portion of the supra- 

 renal organs, augments the activities of the muscles, par- 

 ticularly those of the arterioles. From his recent re- 

 searches, Langley " is disposed to believe that many 

 chemical compounds which augment or diminish the 

 activity of muscles and glands do not act by altering the 

 differentiated tissue, but play upon a hypothetical receptive 

 substance which lies at the junction of the tissue with its 

 entering nerves. This middleman, so situated as to lie 

 in the Interstices of the neuro-muscular junction, bears a 

 relation to the muscle or gland-cell somewhat analogous 

 to that which the fulminating cap bears to the cartridge, 

 and it is quite conceivable that It is maintained in an 

 appropriate condition of Instability or explosiveness by the 

 direct action of chemical substances conveyed to it in 

 minute amounts by the blood. 



It is remarkable how many of these strictly chemical 

 automatic mechanisms have been discovered in the last 

 few years, thus substantiating the views of Brown-Si^quard. 

 The automatic character of the mechanism which deter- 

 mines the secretion of the pancreatic fluid was revealed by 

 the experiments of Bayliss and Starling, which showed 

 that definite chemical compounds are formed in the lining 

 cells of the small intestine, and that treatment with weak 

 acid, such as occurs in the acid chyme, liberates a sub- 

 stance w-hich, absorbed into the blood, has the special 

 function of stimulating the pancreatic cells.' .\ similar 

 automatic mechanism has been found by Edkins to exist 

 in the stomach, for although the flow of gastric juice Is 

 Initiated by nervous channels, the subsequent peptic secre- 

 tion Is largely augmented through the presence in the 

 blood of chemical substances elaborated and absorbed in 

 the pyloric portion of the stomach wall.'' Marshall and 

 Jolly have recently shown that substances elaborated in 

 the maternal ovaries, and particularly in the corous 

 luteum,^ determine, when introduced into the circulating 

 blood, the changes necessary for the proper attachment of 

 the embryo to the uterine wall and thus the further develop- 

 ment of the embryo during the first stages of pregn.Tncy. 

 The researches of Starling and Miss Lane-Claypon indicate 



1 F. Fischer, Fcrkhtt- Deu'.sch. Gesclhchaft, xxxviii 1005. fS-" ako 

 " T.a --vnthe^e des mJ»ncres proleiouf!," par L. C. Maillard, Rd'ue 

 Gfnfrale rfw Srirnccs F4vr. igo6 Paris.) 



2 J. N. Laneley. Journ. fif Physiol.^ xxxiii. 1905, p. 374, and Croonian 

 Lecture. Roy. Soc, 1006. 



^ Ravliss and Starlinc. Jpum, fl/ Physiol, , xxviii. igo2. p. 325. 

 ■> KHlitns, "On the Chemical Mechani.sm of Gastric Secretion," Prac. 

 Roy Soc. B. IxxvT., looc p. 376. 

 '' Marshall and Jolly, Pliil. Trans. Roy. Soc. London, B, 190s, p. 198. 



