Jan. 1 8, 1872J 



NATURE 



229 



Other cells and fibres have other functions as well ; these 

 bodies may have this one function only. They may, in fact, 

 be rudiments of the electric organs of the torpedo, with a 

 sphere of action, not without the body, but within it. And 

 this may be the reason why these bodies are placed on 

 the trunlcs of nerves at points where it may be supposed 

 that special means are wanted for keeping up the requisite 

 degree of elastic tension, their use in this case being 

 analogous to that of an ordinary leyden condenser in con- 

 nection with a telegraph wire conveying a minimum 

 amount of electricity. 



Nor does this view fail to elucidate in some degree the 

 way in which nerves tell upon muscle and react upon each 

 other. Let the contents of the muscular fibre or cell be 

 connected with the contents of the corresponding gan- 

 glionic cell by the axis cylinder of the nerve, and a charge 

 or discharge in the nerve centre must tell upon the mus- 

 cular tissue, just as in the case of two leyden jars with 

 their inner coatings connected by a conductor, the 

 charge or discharge of the one involves corresponding 

 changes in the other. Let the case be that of a sensory 

 peripheral cell and a central ganglionic cell, similarly 

 connected, and a charge or discharge in the former will 

 involve a charge or discharge in the latter, the discharge 

 producing sensation. The case is simply that of a 

 leyden battery, witli all possible space economised by 

 making the conductors, where they may, do the work of 

 the jars. The case is plain as regards the charge, for the 

 molecular charges are ever at work by which it is kept 

 up and renewed ; and the case is not altogether obscure 

 even as regards the discharge, for it may well be that 

 discharge happens when the charge increases until it 

 overleaps the barrier of insulation presented in the 

 dielectric walls of the fibres and cells — a result which, 

 for wane possibly of a sufficiently insulating barrier some- 

 where, happens more easily than it ought to do in the case 

 of involuntary nervous action, such as is seen in convulsion, 

 neuralgia, and the rcs-t. 



Viewed in this way, too, it is easy to sec that the ner- 

 vous system may do its work, not by discharge only, but 

 by charge also. It is easy to see that the discharge may 

 be all that is warned to cause contraction ; indeed, ac 

 cording to the premises, all that is warned for this pur- 

 pose is that the charge which kept the muscular fibre 

 elongated should be discharged, and the fibre so left to 

 the play of its own natural elasticity. It is easy to see, 

 also, that discharge may be the mechanical agent which 

 may call the various nerve-centres into action — by shaking 

 the veil which separates the visible from the invisible in 

 the higher mental processes, perhaps. And for charge no 

 less than discharge it is also easy to see that there may 

 be a definite work to do — a work of which the end is, not 

 to cause action in the muscles and in the various nerve- 

 centres, but to prevent it. Indeed, after what has been 

 said, it is to be supposed that all nerves, through their 

 electricity, have during rest an action which Pfliiger sup- 

 poses to be peculiar to certain nerves only, and to which 

 he gives the name of inhibitory. 



And here opens out a question of paramount in- 

 terest. 



It has been seen that the electric law of nerve and 

 muscle is one and the same. It has been seen that the 

 state of contraction in muscle is antagonised by the pre- 

 sence of a charge of eleciricity in muscle — that a state of 

 actual elongaiion is produced by the action of this charge. 

 It has been seen, not only that the state of contraction is 

 antagonised and a state of elongation set up by the 

 presence of the natural charge of electricity in muscle, but 

 that more marked changes of the same kind are produced 

 by the action of an artificial charge of electricity, provided 

 this charge be greater in amount than the natural charge. 

 The facts, indeed, are calculated to justify the notion that 

 the degree of elongation produced by the conjoint action 

 of the charge belonging to the muscle itself and the charge 



imparted to the muscle from its nervous system is greater 

 than that produced by the action of the former charge 

 singly ; or, in other words, that the charge imparted to 

 I the muscle by its nervous system may cause a degree of 

 ! elongation in the muscle which is over and above that 

 ' caused by the charge belonging to the muscle itself — 

 ! which surplus may have much to do in explaining rhyth- 

 j mical action in hollow muscles. 



Take the case of a hollow muscle — a capillary vessel, 

 I for example. This vessel has its special nervous system, 

 vasomotor nerves, efferent and afferent, vasomotor centre ; 

 and the question is as to how this system acts upon the 

 vessel. May it be that a charge of electricity is continu- 

 ally being developed upon the ceU-walls and fibre-sheaths of 

 this system by the action of the oxygen of the blood and 

 other causes upon the contents of the cells or fibres ; and 

 that this development goes on until, the bounds of insula- 

 i tion being overpassed, discharge happens .'' May it be 

 that the muscular fibres forming the walls of the vessel 

 ! elongate, and in so doing cause the vessel to dilate as long 

 } as this charge is imparted to them.' May it be that the 

 j vessel passes from the state of dilatation into that of con- 

 traction when the discharge of this charge happens, in 

 consequence of the muscular fibres being then liberated 

 from the condition of extra- elongation caused by the 

 charge imparted to them from the nerves, and so left to 

 the play of their natural elasticity ? May it be that thus 

 there are diastolic and systolic changes in the vessel by 

 which the blood is alternately drawn into and driven out of 

 the vessel, changes which may supply the key to the mys- 

 tery of "capillary force"? Nay, more ; may it not be 

 that the diastolic and systolic movements of the heart 

 itself may have to be explained in the same way ? To all 

 these questions 1 answer, unhesitatingly, yes, it may be so. 

 Indeed, after what has been said, the only explanation 

 which seems to be called for concerns the movements of 

 the auricles of the heart, and this is easily given : for, as 

 it seems to me, the auricles must be looked upon chiefly 

 as cisterns formed of dilated veins, and their movements 

 chiefly as passive conseciuences of the movements of the 

 ventricles, the systole of the auricles being little more 

 than the passive falling-in of the auricular walls upon 

 I the blood being suddenly sucked away by the ven- 

 tricular diastole, the diastole of the auricles being little 

 I more than the passive bulging-out of the auricular walls, 

 caused at one and the same time by the stream of 

 blood which is ever flowing in from the valveless 

 openings of the great veins, and by a forcing back of 

 this stream, consequent upon the sudden closure and recoil 

 of the auriculo-ventricular valves at the moment of the 

 ventricular systole. In this way the seemingly diastolic 

 and systolic movements of the auricles must alternate 

 with the true diastole and systole of the ventricles, and, 

 at the same time, the absence of valves at the opening of 

 the great veins into the auricles is accounted for — an 

 absence altogether inexplicable if the auricular systole had 

 to play the active part in the circulation which is played 

 by the ventricular systole. And much to the same eft'ect 

 may be said of rhythmical movements in other hollow 

 muscles, the chief difference between one such movement 

 and another being perhaps this — that contraction follows 

 upon dilatation more slowly in consequence of the cell- 

 walls and fibre-sheaths of the special nervous systems 

 being constructed differently as regards the capacity for 

 quick charging and discharging ; but these hints must 

 suffice for what might be said upon this subject. 

 j Nor can it be urged as an objection to this view of 

 \ nervous action — the only objection which may be urged, so 

 I far as I know — that the state of action in nerve-fibre is 

 I unattended by the contraction which attends upon action 

 i in muscular fibre. The electrical law of nerve and 

 muscle being one and the same, it might be expected, 

 1 perhaps, that this particular difference should not exist ; 

 I but this difficulty, if it be one, is soon disposed of Thus, 



