NA rURE 



[OcTOIiKR 15, 1890 



century do seem to »hark a real epoch in physiology. All along 

 the line, accurate careful observation, quickened by the rapid 

 growth of the cognate sciences, was taking the first steps to 

 replace by sound views the sterile discussions and scholastic 

 disquisitions which had hitherto formed too large a part of 

 physiological teaching. The first steps had been taken, but the 

 most marked advance was yet to come. 



Though the observations of Beaumont had a few years before, 

 by proving tliat gastric juice was a real thing, and demonstrating 

 its properties, shown the nature of digestion in its true light, 

 the older fermentative and other theories were not yet aban- 

 doned by all. Though the conversion of starch into sugar had 

 been recognised, and pepsin had been discovered, the exact 

 action of the digestive juices had yet to be iearnt ; that of pan- 

 creatic juice was almost unknown, and bile still reigned as the 

 king of enteric secretions. 



In the physiology of respiration the view that the carbonic 

 acid of expired air was formed in the lungs by the oxidation of 

 the carbon of the blood, still found strenuous support ; for 

 Johannes Miiller found it necessary to argue at great length that 

 "the researches of Magnus on the gases of the blood had placed 

 the matter in its true light. It had been suggested that the red 

 corpuscles were in some way also special carriers of oxygen from 

 the lungs to the tissues, but Miiller could not regard this as any- 

 thing more than a mere supposition. 



When it is borne in mind that injection with mercury was the 

 one method employed for tracing out the course of the lym- 

 phatics, it will be readily understood how imperfect was the 

 then knowledge of the lymphatic system. And when it is also 

 remembered that though Dutrochet had long before used o.smosis 

 to help in the interpretation of the movements of liquids in living 

 tissues, the exact researches of Graham had yet to come, it will 

 also be understood why, when questions of absorption and 

 cognate questions of secretion came under consideration, they 

 were dealt with as questions in such a condition are dealt even 

 nowadays ; much was said about them because little was 

 known. 



Though Poisseuille, taking up the matter where it had been 

 left by Stephen Hales in the foregoing century, had begun, and 

 the brothers Weber were just continuing, the work of placing 

 our knowledge of the mechanics of the circulation on a sound 

 and exact basis, and though the then leaching of the mechanical 

 working of the heart did not differ widely from that of to-day, 

 the gap which separates the then knowledge of the circulation, 

 even in its mechanical aspects, from that which we possess to- 

 day, is seen in all its width when I remind you that Carl 

 Ludwig's first paper was not published until Huxley had ceased 

 to be a student— until the year 1845. ■'^^ '° "" 'hat great part 

 of the physiology of the vascular system which concerns its 

 government by the nervous system, I will only say that in 

 Midler's great work may be read the pages in which he deals 

 with the conflicting opinions and indecisive observations as to 

 whether the brain and spinal cord have any influence over the 

 heart-beat, and in which, marshalling with logical force the 

 arguments for and against the opinion that the blood-vessels 

 have muscular fibres in their walls, finally decides that they 

 have not. 



In the physiology of the nervous system a momentous advance 

 had been made some few years before, in the early thirties, by 

 the introduction, through Marshall Hall, of the idea of reflex 

 action. This was rapidly supplying the key to many hitherto 

 unsolved physiological and clinical problems. The special 

 functions of the several cranial nerves were being worked out 

 by Majendie, Reid, and others. The former (with Flourens) 

 was also making many experimental researches on cerebral 

 lesicms ; and, in another line of inquiry, Bidder and Volkmann 

 were preparing the way for discoveries to come by their im- 

 portant studies on the sympathetic system. The phy.siology 

 of the senses was being vigorously pushed forward by 

 Johannes Miiller ; but the reader to-day of Miiller's volumes 

 cannot but be struck with the smallness of the space (if we omit 

 all that deals with the .senses) which he allots to the nervous 

 system, when we comjiare it with what is demanded in the 

 present day. And no little part of even that limited space is 

 taken up with a consideration of the law s of those " sympathies " 

 which gave to the sympathetic nerves their name, but which have 

 long since dropped out of sight. 



Lastly, it must he remembered that many of the speculations 

 of the preceding part of the century had remained barren, and 

 many investigations had gone astray through lack of knowledge 



NO. 1407, VOL. 54] 



of the minuter changes which lie at the bottom of physiological 

 events. Those minuter changes could not but lay hidden, so long 

 as there was no adequate knowledge of minute structure. I have 

 already referred to the improvements of the microscope taking 

 place in the thirties, and this soon bore fruit in the rapid growth 

 of that branch of biologic science once called general anatomy, 

 later on microscopic anatomy, and now best known by the name 

 of histology. It is well-nigh impossible to exaggerate the im- 

 portance of a histological basis for physiological deductions ; it 

 is one of the chief means through which progress has been 

 made, and must continue to be made. In the earlier days of 

 phy.siology, the grosser features of structure forming the subject- 

 matter of ordinary anatomy guided the observer to the .solution 

 of problems about functions ; but after a while these became 

 exhausted, having yielded up all they had to yield, and in due 

 time their place was taken by the finer features disclosed by the 

 microscope. These show as yet no signs of exhaustion, and we 

 may look forward in confidence to their standing us in good 

 stead for years to come. We may expect them to last until we 

 pass, insensibly, from that molecular structure which makes itself 

 known by optical changes, to that finer molecular structure 

 which is only revealed by, and inferred from its efi'ects, which is 

 an outcome of the ultimate properties of matter, and which is 

 the condition, and so the cause, of all the phenomena of life. 



The early forties of the present century may t)e taken as 

 marking the rapid rise of histological inquiry. It is true that, 

 even before this, the labours of Henle had gone far ; that in this 

 country the brilliant Bowman had already (in 1840) given to the 

 world his classic work on the structure of striated muscle, and a 

 little later (1842) his hardly less important work on the structure 

 of the kidney ; that the sagacious Sharpey had embodied, in 

 " Quain's Anatomy," a whole host of important histological ob- 

 servations ; and that many others were at work. Nevertheless, 

 one has only to remember how closely the progress of histology is 

 bound up with the name of IColliker, and to call to mind that KiJl- 

 liker's first paper was not published until 1841, to see clearly how 

 much of our present knowledge of histology, and all that that 

 brings with it, has been gathered in since Wharton Jones taught 

 it to the young Huxley. 



If the gap which parts the physiological learning of that time 

 from the learning of to-day is great, still greater is the gap in 

 the teaching. Though at Charing Cross and in some other 

 schools a course of physiology was given, apart from that of 

 anatomy, this was not separately recognised by the College of 

 Surgeons ; it demanded simply a ccjurse of anatomy and 

 physiology, of which the lion's share fell undoubtedly to 

 anatoiny. 



In accordance with this, in most schools, at all events the 

 greater part, and perhaps the sounder part of the physiology 

 taught, was that which may be deduced from anatomical 

 premises. Where the teacher went beyond this, he in most 

 instances at least wandered into academical disquisitions and 

 sterile discussions. Only in rare hands, such as those of Wharton 

 Jones and William Sharpey, was the subject so treated as to be 

 of any real use as a mental training for the medical student pre- 

 paring his mind to view rightly biological problems. The science 

 was not as yet sufficiently advanced to be an educational engine 

 which could be safely entrusted to the ordinary teacher's use. 

 And the method of teaching it, happily recognised now, which 

 alone ensures the salutary influences of the knowledge acquired, 

 that of following out in the laboratory the very steps along which 

 the science has trod, was then wholly unknown. It was as a 

 brilliant favourite pupil that young Huxley was encouraged by 

 Wharton Jones to use the microscope himself, and study among 

 other things the structures of hairs ; he was not led to it, as one 

 of a flock, in a practical course. 



Indeed one kind of knowledge only was at that time demanded 

 of the medical student, in such quantity and in such a way as to 

 render the study of it a real mental training. Not in one year 

 only of his course, but in each year — in his first, his second, and 

 his third year — was the student, who hoped to obtain the diploma 

 of the College, compelled to attend lectures, each course con- 

 sisting not as in other subjects of seventy, but of double that 

 number of lectures, on what was styled anatomy and physiology, 

 but was in the main what we now call anatomy. Moreover, the 

 student learnt even then his anatomy in the same way that he is 

 bid to learn all other subjects now, not merely by listening to 

 lectures, or even by witnessing formal demonstrations, but by 

 individual labour in the laboratory, in that laboratory which we 

 call a dissecting-room. Nowadays it may seem strange to insist 



