?21z 



PHYSIOLOGY OF THE NERVOUS SYSTEM. 



The aggregate of these fibres, together with 

 the grey mutter, constitutes the true xpinal cord 



of Dr. Hull, which is not limited to the spinal 

 canal, but passes up into the cranium as tar as 



pathetic actions, have not, I affirm, associated one 

 physiological act with any such reflex function of the 

 spinal marrow. This is, therefore, my discovery." 

 Upon this passage I must remark, 1st, that if Dr. 

 Hall merely claims the discovery of the reflex func- 

 tion, it cannot be conceded to him, for Prochaska 

 had already distinctly announced the existence of 

 this function in the medulla oblongata and spinalis, 

 using even the term functio , as in the following pas- 

 sage : " Cum itaque preecipua fimctio sensorii 

 communis consistat in reflexione impressionum sen- 

 soriarttm in motorias, notandum est, quod ista re- 

 rlcxio vel animanesciu, vel vero anima consciafiat." 

 Loc. cit. pp. 118-19. 



If, however, Dr. Hall claims the discovery of this 

 function " ax the nervous agent in all the nets of inaes- 

 tii.ni. and egestion in the animal economy," then I have 

 only to remark that I know of no physiologist in 

 the present or in former times who would care to 

 dispute such a discovery with him. I have already 

 shown that the id -a that these acts of ingestion and 

 egestion are dependent on this function is a hction 

 of the fancy an idolon specus which rests upon 

 an imperfect and erroneous analysis of these acts, 

 and on very narrow views of the nature and mode 

 of dcvelopemeiit of the nervous force. If, finally, 

 Dr. Hall limits his claims, as he says he might do, 

 to the discovery (?) of the anatomy and physiology 

 of the true spinal system, as a combined system of 

 ' 1, incident nerves, 2, their spinal centre ; and, 3, 

 reflex nerves, constituting the anatomy of the whole 

 series of the acts of ingestiou and egestion," I am 

 quite sure that no anatomist or physiologist of the 

 present day would seek to deprive him of such a 

 discovery, or dispute the opinion of Professor 

 Flonrens that it belongs to Dr. M. Hall. That this 

 so-called true spinal system is no more than an hy- 

 pothesis, and one which has but an infirm basis to 

 rest upon, 1 have endeavoured to show in the text. 

 That a centre of reflex actions exists but not dis- 

 tinct from the centres of season-volitional acts 

 every physiologist will admit, and the limits of that 

 centre were most correctly defined more than fifty 

 years ago by Prochaska under the name sensuriiun 

 commune, which extends, according to him, " quana 

 late patet nervorum origo," and which, as I have 

 already remarked, completely foreshadowed Dr. 

 Hall's " true spinal marrow." 



In sections 5 11 of this work Dr. Hall states 

 the real objects of his researches as follows. 



" First, to separate the reflex actions from any 

 movements resulting from sensation and volition. 



Secondly, to trace these actions to an acknow- 

 ledged source or principle of action in the animal 

 economy the vis nervosa of Haller acting ac- 

 cording to newly discovered taws. 



Thirdly, to limit these actions to the true spinal 

 marrow, with its appropriate incident and reflex 

 nerves, exclusively of the cerebral and ganglionic 

 systems. 



Fourthly, to apply the principle of action in- 

 volved in those facts to physiology, viz. to the 

 physiology of all the acts of exclusion, of inges- 

 tion, of retention, and of expulsion in the animal 

 frame. 



Fifthly, to trace this principle of action in its 

 ichition to pathology, viz. to the pathology of the 

 entire class of spasmodic diseases ; and, 



Sixthly, to shew its relation to therapeutics, 

 especially to the action of certain remedial and cer- 

 tain deleterious physical agents. 



Finally, it is to these objects, taken together as 

 airhole or us a. system, that I prefer my claims; 

 and I do not pretend that an occasional remark 

 may not have been incidentally made by some 

 previous writer, bearing upon some one or other 

 of them." 



It is in this work that Dr. Hall has, for the first 



time, ventured to notice the remarkable views of 

 Prochaska. I wish, for the sake of English phy- 

 siology, and also for the sake of Dr. Hall's own 

 character as one who professes great admiration 

 for those who " display a randid, impartial, and 

 generous judgment of the works of others," that the 

 extracts which he has made from Prochaska's work, 

 few and imperfect as they are, had been accompa- 

 nied by some more dignified and more ingenuous re- 

 marks than those contained in the following para- 

 graph. 



" It is impossible to adduce specimens of more 

 complete confusion than these, in which voluntary 

 acts, and the actions of the heart, stomach, and 

 intestines functions of the cerebral and of the grin- 

 ylio/iic systems respectively, are arranged with 

 certain reflex experimental facts, and very obvious 

 sympathetic actions, which really belong to the 

 true spinal system." 



1 have carefully examined the passages quoted 

 from Prochaska by Dr. Hall, and I confess myself 

 unable to discover any of that " complete con- 

 fusion to which he alludes." Prochaska states, 

 that numerous examples (pluriiua exempla) prove 

 the general law of the reflecting power of the 

 sensorium commune, of which, however, he sa\s, 

 it will suffice to adduce only u few. He mentions 

 sneezing produced by irritation of the mucous 

 membrane of the nostrils,* the violent cough pro- 

 duced by irritation of the glottis per micam cibi 

 vel guttulam potus illapsatn, and the winking ex- 

 cited by bringing the linger close to the eye. If 

 these are not fair examples of reflex actions, I 

 know not what are. 



Prochaska then proceeds to show that these 

 reflex actions may take place with or without the 

 cognizance of the mind; and here I must refer to 

 a very disingenuous proceeding on the part of 

 Dr. Hall in his quotations. He displaces the pas- 

 sages irom their right order and therefore from the 

 context, and thereby introduces an appearance of 

 confusion which does not exist in the original. 

 The passage commencing " Si amicus digito," c. 

 occurs before and in a different paragraph from 

 that commencing " Cum itaque pra?cipuo," vStc., 

 Dr. Hall quoting them as if the latter stood first. 

 He has similarly transposed the passages com- 

 mencing " Sed fieri tamen," c. and " Motus 

 cordis, ventriculi." 



In the remaining portion of this work Dr. Hall 

 has systematized his views more completely than 

 in his previous writings repeating, however, much 

 the same experiments, re-asserting the same expla- 

 nations of certain actions as before, and adding 

 some new remarks in vindication of his views al- 

 ready expressed. Yet in this volume there are 

 indications as if Dr. Hall had no great confidence 

 in his own hypothesis, notwithstanding he had 

 thought it worthy of being designated a discovery. 

 At $ 149, referring to Dr. Carpenter's and Mr. 

 Newport's opinions in favour of the existence of 

 excito-motory fibres distinct from sensori-volitional 

 fibres, he remarks, " I doubt not that the investi- 

 gations of these gentlemen are correct ; they have, 

 therefore, confirmed what I had long previoiifly 

 done." But in J 150, having mentioned Mr. Grain- 

 ger's assertion that in the roots of the spinal nerves 

 one set of fibres passes up to the brain, while the 

 other pursues its course to the grey matter, he says, 

 " It is probable, therefore, that the former are in 

 reality nerves of sense and voluntary motion, whilst 

 the latter are the nervous channels of the excito- 



* Prochaska supposes that the olfactory nerves 

 propagate, the irritation which excites sneezing to 

 the centre ; the office of the fifth nerve was not 

 made out in his day. 



