August II, i8Si] 



NA TURE 



349 



that modern ophthalmology ha^ scarcely a single point of simi- 

 larity with that of the last century? Who contents himself with 

 the symptom of amaurosis ? Who despairs of recognising in it 

 the existence of glauc.ima? Every ophthalmic surge jn has in 

 his hands the means of studying the thing itseU, and not merely 

 its signs, liven the anti-vivi^ectors acknowledge that ophthal- 

 mology is a study that is capable of effecting something. But 

 they forget that every organ of the body is not so favourably 

 placed and arranged for the observation of its inuer proce-ses as 

 is the eyeball, t^ince the wonderful discovery of the ophthalmo- 

 scope, auatomical analysis, even without the use of the knife, 

 has become capable of penetrating so far into the individually 

 remote, that we can immediately observe and s;udy by them- 

 selves the smallest features of the fundus oculi, even, indeed, 

 its single cells, or groups of cells, just as in an artificial prepara- 

 tion of an eye that has been excised. But it mu t not be for- 

 gotten that long anatomical and physiological s'udies have been 

 a necessary preliminary to the interpretation of that which is 

 now so easUy perceived. 'Ihe structure, arrangement, and 

 function of each single part had first to be laboriously established 

 before it was possible, by a transitory glance at the altered tissue, 

 to reco;jnise what is especially changed ; and no medical man 

 will attain to a true comprehension of the essence of these 

 changes if he have not previously learned to recognise most accu- 

 rately the anatomical and physiological nature and the possible 

 pathological changes of the individual constituent parts of the 

 eye. 



They speak lightly who- object to us, that not all the branches 

 of medicine stand on the same height with ophthalmology. ITiat 

 will never be the case. Just as it is easier to explore the sea in 

 its depths than the solid land, so will the most transparent organ 

 of the body always be the most convenient place for medical 

 diagnosis and treatment. While it is possible to ob-erve with- 

 out difficuliy a cysticercus in the hinder part of the retina, one 

 will always be taught to bring a cysticercus of muscle or a 

 trichina in a patient to light by vivisection. Never can it be 

 required that every medical specialty should altogether equal 

 ophthalmology in security of treatment and diagnosis ; but any 

 measure of success can only be sought in the use of the ophthal- 

 mological meth )d in a corresponding manner in the other special 

 departments. This method, ho%\'ever, is anatomical, or, as it 

 has otherwise been expressed, localising. 



With this, we have reached the point which denotes the 

 boundary between ancient and mode-.n medicine. The principle 

 of modem mcdiciiu is localisation. To those who still constantly 

 ask of what use modern science has been to practical medicine, 

 we can simply point out that every branch of medical practice 

 has accommodated itself to the principle of localisation, not only 

 in pathology, but also in therapeutics, and that there^iy the 

 greatest benefit has accrued to the sick. It is quite superfluous 

 to seek out single examples in order to show what profit the new 

 knowledge has brought. Such examples are abundant. But we 

 do not require them, for we can point to the general character of 

 modern medicine. All those studies which already at an earlier 

 period had a natural tendency to localisation, such as special 

 surgery and dermatology, have in this way been raised to their 

 present state of perfection. Those, however, which have 

 retained from the old humoral pathology a tendency to the 

 establishment of generalising formulae gradually renounce the 

 favourite tridition ; and the fact is more and more compi ehended, 

 that generalis tion in truth is no'hing else than multiplication of 

 foci, and that the cure of a so-called general disease signifies just 

 as much as the eradication of a single focus. That was in fact a 

 reform in head and limbs ; and he who has not grasped it ought 

 not to say that he has consciously followed the progress of 

 science. 



The notion of the general validity of the doctrine of the 

 localisation of disease and of the multiplication of foci of disease 

 in the same individual, stands, as was often objected to me in 

 the beginning of my career as a teacher, in strict opposition to 

 the idea of the unity of disease, or, as it is expressed in customary 

 language, to the ens tnorbi. My former colleagues sti 1 retained 

 large portions of this idea ; they believed that the practical 

 physician entered into arbitrary, and therefore dangerous, specu- 

 lations, when, in the presence of a single case of disease, he 

 .assumed the disease to be a plurality. To me it seems rather 

 the reverse ; that the physician enters on a fruitless project [sche- 

 matismus), and one dangerous to his patients, if he suppose 

 each individual case of disease to correspond to the opinion of 

 his school or his own private view, and calculate his prognosis 



and treatment thereby. Meanwhile, these considerations, de- 

 rived from medical practice, on the ulility of a certain way of 

 perceiving disease, can lead to no decision as to its truth, and 

 yet, at this result only is it possible to arrive. How shall we 

 establish it ? 



All the world is at one on this point, that disease presupposes 

 life. In a dead body there is no disease. Wiih death, lite and 

 disease disappear simultaneously. This consideration led the 

 older ]ihysicians to assume disease to be a self-living or even 

 animated essence, which took its place in the body along with 

 the vital principle. Many went so far as to define disease as a 

 combat between two contending principles, the innate life and 

 an intrusive foreign body. But all ca ne liack to life as a preli- 

 minary condition of disease. The view was first list in the old 

 Leyden school ; from Bocrhaave emanated ihe dogma, which 

 his pupil Gaubius placed at the head of his lungu-ed " Hand- 

 book of General Pathology," the first written on the subject : 

 Morbus est vita premier naturam. Disease is life itself ; or, to 

 speak more correctly, it is a portion of life. 



This assumption displ: ced the unfortunate dualism which had 

 so long dominited medicine; or, at least, it ouuht to have 

 displaced this dualism between life and disease. If, neverthe- 

 less, it has not completely done this, and if more than a century 

 has been required to break up the still constantly existing dis- 

 sonance, the reason lies in the difficulty of finding a satisfactory 

 conception of life. And here the quest! m must not lie pissed 

 by. Where has life its special seat? UH sedcs jitit? John 

 Hunter went back to the ancient view, already expressed in the 

 Mosaic formula: "The life of the body is in Us blood." 

 Fl lurens believed that he had found the seat of li'c, the nceud 

 vital, in the central nervous system, in the medulla 'iblongata. 

 The one, like the other, found himself obliged to institnte ex- 

 periments on living animals for the investigaiion oi this difficult 

 question. Therev\ith the experimental method in the more strict 

 sense began to pass into the practice of pathologists. Vivisec- 

 tion became a regular aid to research. 



Certainly the consideration that a knowledge of life can only 

 be obtained on the living being was \aai present. Beyond 

 doubt it was already formed in antiquity. But it is difficult to 

 determine with accuracy the time when it first liecame pnctically 

 active. Uncertain statements only on the subject are available. 

 Zacharias Sylvius, a physician of Rotterdam, who wrote the 

 preface to the Dutch edition of Harvey's " Exercitaticmes," calls 

 to mmd the tale of Democritus, whom the Abderiles rci^arded 

 as insane, ' ecause they saw him constantly engaged in vivisec- 

 tion ; when houever the great Hippocrates was sent for to cure 

 him, he fully recognised the value of his proceedings, and de- 

 clared that all the Abderites w-ere lunatics, and that Democritus 

 alone was sane.' Probably this story has been narrated at the 

 expense of the good Abderites ; but it still show^ that vivisec- 

 tion already "lay in the air." I will not attempt to decide 

 whether it is true that the teachers in the Alexandrian school 

 actually availed themselves of the permission of their king to 

 dissect criminals. The only conclusion which I can derive from 

 these tales is that researches on animals must surely have at that 

 time been already practised. For whoever reflects on the vivi- 

 section of men must acknowledge that, especially at a time when 

 the anatomy of animals formed the foundation of meoie;d study, 

 vivisection had certainly been previously done on animals. In 

 the scho il of the empirics which proceeded from that of Alex- 

 andria, and in which necropsy w.as taught as the chief means of 

 knowledge, experiment also appears as having a recognised 

 claim ; in the celebrated formula, which has been called the 

 tripod of the empirics, and which served as the programme of 

 their school, deliberately-planned experiment is expressly men- 

 tioned (^i/o-i/cT) ^ ouT0irx*5i'7| T7)p7)<ru). Only it is not evident to 

 what extent this research on living animals was carried on. 

 Hence it is also unprofitable to inquire what advantage of any 

 kind ancient medicine derived from vivisection. 



In fact, the first great and distinctive example of successful 

 vivisection which the history of medicine Knows is that of 

 William Harvey. The foundation of the doctrine of the circu- 

 lation, which in the main was experimental, has radically 

 changed the whole direction of the thoughts of physicians. 



^ " Harveji Exercit. Anat," Roterod 

 solertissinius operum natursc perscrui 

 ccciiparetur, existimatus fuit 

 hominis advocarunt_^HippocrateiT 



671. " Pr^fati 



ab Abde-iiis: qui m 

 medicii lam facerei m-, 

 ofFendit Dem >crituin i 



uloi 



olum sapere Demociitum.' 



oblectatus, 



s ^bdentas insanire 



