122 



MATURE 



[January 26, 1922 



Physiology at the British Association. 



THE outstanding features of this most successful 

 meeting at Emnburgh were the large number of 

 discussions and the giving of an official semi-popular 

 lecture. Before the beginning of the latter a very 

 pleasant interlude was furnished by Prof. Halliburton 

 announcing a presentation to Sir Edward Sharpey 

 Schafer on his seventieth birthday by his former 

 students and co-workers. 



The address of the president of the section was 

 followed by a debate. Sir E. Sharpey Schafer dis- 

 cussed three points in connection with physiology, 

 namely, the position of histology, physiology as a pure 

 science, and physiology in relation to clinical medicine. 

 He stated that anatomy is not a dead subject 'without 

 histology, as it can be developed along the lines of 

 morphology and embryology, but that histology is 

 essential for the proper understanding of physiology. 

 He further pointed out that, although it can be called 

 microscopic anatomy, histology has developed as a 

 branch of physiology. The study of physiology as a 

 pure science is necessary, because it is in the pursuit 

 of knowledge that discoveries are made. It is not 

 always known what practical applications may arise 

 for new knowledge, but by confining one's attention 

 to purely practical applications the reserve of know- 

 ledge to be applied will become exhausted. The 

 application of physiology to clinical medicine should 

 come by the clinical teacher having held a position in 

 the physiological laboratory. The physiologist has 

 sufficient work to accomplish in his laboratory without 

 attempting to become a clinician. By the proper 

 training of clinical teachers in physiology it is hoped 

 that invaluable applications will arise in medical 

 practice. 



A number of other speakers took part, all of whom 

 enforced the views of Sir Walter Fletcher that physio- 

 logy must be studied as a pure science in a university ; 

 that the physiologist should study the organism as a 

 whole, so that histology, chemistry, and physics all 

 may be applied to explain the behaviour of living 

 organisms ; and that it is only by a combination of 

 all these that one can appreciate to what extent the 

 chemical and physical processes may be regulated in 

 the living cells. 



Prof. A. R. Cushny opened a discussion on the 

 relation of tests for studying the efficiency of the 

 kidney to the views as to the function of the kidney. 

 Various tests have been used to test the functional 

 activity of the kidneys without a proper consideration 

 of the conditions of its activity. The excretable sub- 

 stances must be distinguished from the non-excretable. 

 The threshold substances are those which are excreted 

 when their concentration rises above a certain thres- 

 hold, and the no-threshold substances are those which 

 are completely excreted, i,e. they are of no further use 

 to the organism. Of the various substances used, 

 water, chlorides, and urea are not satisfactory, as they 

 are not completely excreted. By comparing the 

 amount of urea and sulphate in blood and urine it 

 has been found that sulphate is concentrated twice 

 as much as urea, so that the functional activity as 

 judged by the sulphate excretion would be twice as 

 great as when judged by the urea excretion. Sul- 

 phate, phosphate, and creatinine were concentrated to 

 equal degrees ; therefore, the concentration of any of 

 these in plasma and in urine might be measured as 

 a test for functional activity. 



Prof. J. Meakins commenced by agreeing that urea 

 is not a toxic substance. He quoted cases where 

 chronic incomplete obstruction of the ureter gave rise 

 NO. 2726, VOL. 109] 



to a large volume of dilute urine. H temporary re- 

 moval of the obstruction causes the kidney function to 

 become normal, this is an indication for surgical inter- 

 ference ; but if the excretion does not become normal, 

 surgical interference is contra-indicated. Sometimes 

 one finds that a no-threshold substance (e.^. creatinine) 

 is being retained. Retention of urea by itself is not 

 important, because along with this retention one may 

 find such conditions as an excessive excretion of phos- 

 phates or a retention of chlorides, which are jnore 

 responsible for the symptoms. The kidney does not 

 function as a whole under abnormal conditions, and 

 if one adheres too rigidly to one criterion of functional 

 efficiency abnormalities may be overlooked. 



Dr. J. S. Haldane expressed the view that under 

 normal conditions the kidney regulates the diffusion 

 pressure of water, but that under some abnormal 

 conditions the level set by the kidney is not that 

 required by the tissues. 



Prof. P. T. Herring showed some slides of the 

 skate's kidney, which demonstrated the direct excre- 

 tion of substances into the kidney tubule. He stated 

 that normally the kidney has a constant function, 

 but in disease the function is variable, being influenced 

 by other organs. A study of the comparative structure 

 of the kidney in various animals may help to show 

 how various parts of the kidney tubule function ; part 

 may be absorptive and part excretive. 



Prof. A. Krogh (Copenhagen) pointed out that the 

 concentration of urea is the same throughout the 

 tissues, but that it may be present in different concen- 

 trations in the various secretions. 



Prof. T, H. Milroy re-emphasised the uniformity in 

 concentration of urea in blood and muscle. He added 

 that an increase in concentration of urea in the blood 

 is followed by a latent period before the extra urea is 

 eliminated. The concentration in blood and muscle 

 falls slowly to the former level. 



Dr. C. L. Evans thought that local circulatory 

 changes in difTerent parts of the kidney might affect 

 the excretion of different substances by different parts 

 of the tubule. The circulatory changes in arterio- 

 sclerosis is a case in point. 



Dr. E. p. Poulton stated that in the arterio-sclerotic 

 kidney there is a marked difference between the two 

 parts of the kidney and slight urea retention. In 

 azotoic nephritis urea excretion is damaged, but the 

 chlorides are not retained. 



Sir James Mackenzie desired that more attention 

 should be paid to the interrelation of kidneys and other 

 excretory organs, such as the skin and bowels. 



Prof. E. P. Cathcart opened a discussion on '* Heavy 

 Muscular Work." Heavy muscular work requires a 

 co-ordination of the muscular, circulatory, respiratory, 

 and nervous systems. In carrying out heavy work 

 rest periods are important, but the data concerning 

 the number and duration of them are not yet satis- 

 factory. Overwork is prevented by two factors of 

 safety, namely, fatigue, which is slow in onset and 

 may be produced by any degree of work, and collapse, 

 which is sudden in onset, probably due to heart failure, 

 and not to lack of oxygen-supply to muscles. The 

 former is hastened by monotony, such as in marching, 

 and the latter occurs sooner if the work involves a 

 static or maintained element. The effects of training 

 and of diet are important in determining the power 

 to carry on work. All movements are mixed, but 

 some recent experiments may be quoted as indicating 

 a division into three varieties of work, namely, posi- 

 tive, such as lifting a weight ; negative, such as 



