September 2, 1S97] 



NA TURE 



4.i7 



ing what is the exact nature of the fundamental changes which 

 bring about contraction and what are the relations of those 

 changes to the structure of muscular fibre. In respect to 

 another old problem, too, the beat of the heart, we have con- 

 tinued to creep nearer and nearer to the full light. Problems 

 again, the method of attacking which is of more recent origin, 

 such us the nature of secretion, and the allied problem of the 

 nature of transudation, have engaged attention and brought 

 about that stirring of the waters of controversy which, whatever 

 be its effects in other departments of life, is never in science 

 wholly a waste of time, if indeed it be a waste of time at all, 

 since, in matters of science, the tribunal to which the combat- 

 ants of both sides appeal is always sure to give a true judgment 

 in the end. In the controversy thus arisen, the last word has 

 perhaps not yet been said, but whether we tend at present to 

 side with Heidenhain, who has continued into the past thirteen 

 years the brilliant labours which were perhaps the distinguish- 

 ing features of physiological progress in preceding periods, and 

 who in his present sufferings carries with him, I am sure, the 

 sympathies if not the hopes of all his brethren, or whether we 

 are more inclined to join those who hold different views, we 

 may all agree in saying that we have, in 1897, distinctly clearer 

 ideas of why secretion gathers in an alveolus or lymph in a 

 lymph space than we had in 1884. 



I might multiply such examples of progress on more or less old 

 lines until I wearied you ; but I will try not to do so. I wish 

 rather to dwell for a few minutes on some of what seem to be the 

 salient new features of the period under review. 



One such feature is, I venture to think, the development of 

 what may perhaps be called the new physiological chemistry. 

 We always are, and for along time always have been, learning 

 something new about the chemical phenomena of living beings. 

 During the years preceding those immediately recent, great 

 progress, for which we have especially, perhaps, to thank 

 Kiihne, was made in our knowledge of the bodies which we 

 speak of as proteids and their allies. But while admitting to 

 the full the high value of all these researches, and the great 

 light which they threw on many of the obscurer problems of 

 the chemical changes of the body, such, for instance, as the 

 digestive changes and the clotting of blood, it could not but be 

 felt that their range was restricted and their value limited. 

 Granting the extreme usefulness of being able to distinguish 

 bodies through their solution or precipitation by means of this 

 or that salt or acid, this did not seem to promise to throw much 

 light on the all-important problem as to what was the connection 

 between the chemical constitution of such bodies and their work 

 in the economy of a living being. For it need not be argued 

 that this is an all-important problem. To-day, as yesterday and 

 as in the days before, the mention of the word vitalism or its 

 equivalent separates as a war-cry physiologists into two camps, 

 one contending that all the phenomena of life can, and the 

 other that they cannot, be explained as the result of the action 

 of chemico- physical forces. For myself, I have always felt 

 that while such a controversy, like other controversies as I 

 ventured to say just now, is useful as a stirring of the waters, 

 through which much oxygen is brought home to many things 

 and no little purification effected, the time for the final judg- 

 ment on the question will not come until we shall more clearly 

 understand than we do at present what we mean by physical and 

 chemical, and may perhaps be put off until somewhere near the 

 end of all things, when we shall know as fully as we ever shall 

 what the forces to which we give these naines can do and what 

 they cannot. Meanwhile the great thing is to push forward, so 

 far as may be, the chemical analysis of the phenomena presented 

 by living beings. Hitherto the physiological chemists, or the 

 chemical physiologists as perhaps they ought rather to be called, 

 have perhaps gone too much their own gait, and have seemed 

 to be constructing too much a kind of chemistry of their own. 

 But that, may I say, has in part been so because they did not 

 receive from their distinctly chemical brethren the help of which 

 they were in need. May I go so far as to say that to us physio- 

 logists these our brethren seemed to be lagging somewhat 

 behind, at least along those lines of their science which directly 

 told on our inquiries? That is, however, no longer the case. 

 They are producing work and giving us ideas which we can 

 carry straight into physiological problems. The remarkable 

 work of Emil Fischer on sugars, one of the bright results of my 

 period of thirteen years, may fully be regarded as opening up a 

 new era in the physiology of the carbohydrates, opening up a 

 new era because it has .shown us the way how to investigate 



NO. 1453. VOL. 56] 



physiological problems on purely and distinctively chemical 

 lines. Not in the carbohydrates only, but in all directions our 

 younger investigators are treating the old problems by the new 

 chemical methods ; the old physiological chemistry is passing 

 away ; nowhere, perhaps, is the outlook more promising than 

 in this direction ; and we may at any time receive the news 

 that the stubborn old fortress of the proteids has succumbed to 

 the new attack. 



Another marked icature of the period has been the increasing 

 attention given to the study of the lower forms of life, using 

 their simpler structures and more diffuse phenomena to elucidate 

 the more general properties of living matter. During the 

 greater part of the present century physiologists have, as a rule, 

 chosen as subjects of their observations almost exclusively the 

 vertebrata ; by far the larger part of the results obtained during 

 this time have been gained by inquiries restricted, to some half 

 a dozen kinds of backboned animals ; the frog and the myograph, 

 the dog and the kymograph have almost seemed the alpha and 

 the omega of the science. This has been made a reproach by 

 some, but, I cannot help thinking, unjustly. Physiology is, in 

 its broad meaning, the unravelling of the potentialities of things 

 in the condition which we call living. In the higher jCnimals 

 the evolution by differentiation has brought these potentialities, 

 so to speak, near the surface, or even laid thfem bare as actual 

 properties capable of being grasped. In the lower animals they 

 still lie deep buried in primeval sameness ; and we may grope 

 among them in vain unless we have a clue furnished by the 

 study of the higher animal. This truth seems to have been, 

 early recognised during the progress of the science. In the old 

 time, observers such as Spallanzani, with but a moderate 

 amount of accumulated knowledge behind them, and a host of 

 problems before them, with but few lines of inquiry as yet 

 definitely laid down, were free to choose the subjects of their 

 investigation where they pleased, and in the wide field open 

 to them prodded, so to speak, among all living things, indifferent 

 whether they possessed a backbone or no. But it soon became 

 obvious that the study of the special problems of the more highly 

 organised creature was more fruitful, or at least more easily 

 fruitful, than that of the general problems of the simpler forms ; 

 and hence it came about that inquiry, as it went on, grew more 

 and more limited to the former. But an increasing knowledge 

 of the laws of life as exemplified in the differentiated phenomena 

 of the mammal is increasingly fitting us for a successful attack 

 on the more general phenomena of the lowly creatures possess- 

 ing little more than that molecular organisation, if such a phrase 

 be permitted, which alone supplies the conditions for the 

 manifestation of vital activities. And, though it may be true 

 that in all periods men have from time to time laboured at this 

 theme, I think that I am not wrong in saying that the last dozen 

 years or so mark a distinct departure both as regards the number 

 of researches directed to it, and also, what is of greater moment, 

 as regards the definiteness and clearness of the results thereby 

 obtained. One has only to look at the results recorded in the 

 valuable treatises of Verworn and Biedermann, whether obtained 

 by the authors themselves or by others, to feel great hope that 

 in the immediately near future a notable advance will be made in 

 our grasp of the nature of that varying collection of molecular con- 

 ditions, potencies and changes, slimy hitherto to the intellectual 

 no less than to the physical touch, which we are in the habit of 

 denoting by the more or less magical word protoplasm. And 

 perhaps one happy feature of such an advance will be one step 

 in the way of that reintegration which men of science fondly hope 

 may ultimately follow the differentiation of studies now so fierce 

 and attended by many ills ; in the problems of protoplasm the 

 animal physiologist touches hands with the botanist, and both 

 find that under different names they are striving towards the 

 same end. 



Closely allied to and indeed a part of the above line of inquiry 

 is the study of the physiological attributes of the cell and of 

 their connection with its intrinsic organisation. This is a study 

 which, during the last dozen years, has borne no mean fruits ; 

 but it is an old study, one which has been worked at from time 

 to time, reviving again and again as new methods offered new 

 opportunities. Moreover, it will probably come directly before 

 us in our sectional work, and therefore I will say nothing more 

 of it here. 



Still another striking feature of the past dozen years has been 

 the advance of our knowledge in regard to those events of the 

 animal body which we have now learnt to speak of as " internal 

 secretion." This knowledge did not begin in this period. The 



