November 6, 1919] 



NATURE 



207 



DEVELOPMENTS OF PHYSIOLOGY. 



By Sir Edward Sharpey Schafer, F.R.S. 



MOST of the fundamental facts of physiology 

 had been discovered before 1869, but 

 nearly all the progress in the nineteenth century 

 up to that time was made in France and 

 Germany ; and those who wished to learn 

 the subject properly had perforce to seek 

 instruction abroad — a condition of affairs which 

 is fortunately in great measure now re- 

 versed. During the sixties of last century physio- 

 logy had ceased to exist as an active science in 

 this country. There were no laboratories, and 

 no systematic investigations of a physiological 

 character were carried on. The men who pro- 

 fessed the subject in our medical schools were 

 physicians or surgeons who were switched on to 

 it as it came to their turn, and imparted to their 

 hearers such knowledge as they might have 

 acquired from books, but were themselves igno- 

 rant of the methods and aims of the science they 

 were appointed to teach. 



There was, however, one notable exception in 

 William Sharpey, who was called from Edinburgh 

 to fill the newly-constituted chair of general 

 anatomy and physiology in University College, 

 London, in 1836, and retained it until 1874. 

 Sharpey, although a great teacher, was not really 

 a physiologist. His training was wholly that of 

 an anatomist, and his teaching was largely 

 anatomical. Of the physiology he taught very 

 little was acquired as the result of personal 

 investigations, and his knowledge of the methods 

 employed in modern physiology was nil. But he 

 had clear ideas regarding the principles of the 

 science, and an extraordinary facllitv for impart- 

 ing his ideas and for Interesting his hearers In 

 them, so that when the opportunity came for 

 learning the methods thej' were in an advan- 

 tageous position to pursue the subject. 



It was a pupil of Sharpey — Michael Foster — 

 who founded the famous school of physiology at 

 Cambridge, and it was through Sharpey 's influ- 

 ence that Burdon Sanderson was induced to give 

 up the practice of medicine In order to install 

 the practical teaching of physiology in London. 

 These were the pioneers, and their influence gradu- 

 ally spread, so that before very long I^ngland 

 succeeded in again taking a foremost place in a 

 science which may be said to have had its birth 

 in our country, for before the immortal discovery 

 of Harvey no true physiology was possible. 



The development of the science during 'the last 

 fifty years has occurred partly along the old lines, 

 which have been thrust forward far in advance 

 of the position they occupied half a century ago, 

 partly on new lines which were at that time not 

 only untraced, but even unthought of. The 

 immense progress on the old lines of investigation 

 is evident whatever be the branch of the science 

 to which we may turn our attention. This pro- 

 gress is actively correlated with the parallel 

 NO. 2610, VOL. 104] 



development of the sciences upon which physio- 

 logy is based — physics and chemistry. More 

 than all, perhaps, has physical chemistry — a 

 branch of science which, if already born fifty 

 years ago, had at any rate not been baptised — 

 enabled the physiologist to see — if still very 

 dimly — into the processes which make up life 

 itself further than could ever have been dreamed 

 of in those distant days. 



To give an account of the progress which has 

 been made on the old lines of investigation would 

 occupy a large volume ; the shortest description 

 would take many pages. Fifty years ago nothing 

 was known of the constitution of the proteins or 

 of the manner in which they are built up into the 

 tissues. The mode of action of the heart and 

 the factors which regulate circulation and respira- 

 tion were still obscure. The localisation of func- 

 tions in the brain had not been discovered. The 

 important changes which cells undergo in the per- 

 formance of their functions and in multiplication 

 were unknown. The relation of the sympathetic 

 to the rest of the nervous system was in no way 

 understood. But perhaps the most striking fact 

 which has come out as the result of modern in- 

 vestigation is the dominant action of the central 

 nervous system upon all physiological processes. 

 Not that this is entirely new; it was undoubt- 

 edly indicated before the period with which we 

 are dealing. But the paths and manner of its 

 action have been so thoroughly studied, and the 

 accumulation of evidence regarding it has become 

 so great, that one may fairly look upon this as 

 the most Important development of physiology 

 along the lines it was pursuing some fifty years 

 since. That this advance has been assisted by 

 the remarkable conception of the structure of the . 

 nervous system, which we owe in the first in- 

 stance to an anatomist — Golgi — is willingly con- 

 ceded, for it must be admitted that our under- 

 standing of the mode of action of the nervous 

 system has become vastly simplified thereby. 



The new lines on which the science has under- 

 gone development within the period with which 

 we are dealing relate to the influence of chemical 

 agencies in regulating the functions of the body. 

 New lines, do I say? Nothing under the sun 

 is ever entirely new. From the earliest times 

 with which history deals, and doubtless even in 

 prehistoric days, it was known that the functions 

 of the body are affected by chemical agencies. 

 For have not drugs, many of them of a potent, 

 not to say poisonous, nature, been administered 

 from time immemorial? Was it not known 

 that the chemical condition of the circulating 

 fluid influences the. functions of some organs ; 

 that an excess of CO„ in the blood affects 

 respiration, an excess of sugar the kidneys; 

 whilst any alteration in its constitution or re- 

 action is liable to have a deleterious action 



