500 



♦ KNOWLEDGE • 



[June 12, 1885. 



The first is a saw which makes a number of longitudinal 

 cuts (in this case, eight) ; the next is a cutting tool which 

 enlarges the gi'ooves and brings the leaves appioximately 

 to shape; while the third, also a cutting tool, finishes them. 

 All these operations are gone through in seventy seconds, 

 and, when completed, the machine automatically stops 

 working. The pivots have then to be finished, after which 

 the pinion is hardened and polished, the polishing being 

 done automatically and cleverly. In polishing the leaves, 

 a polisher (of tin) is used which passes between the leaves, as 

 they are jiresonted to it by a little steel finger. Subse- 

 quently each pinion requires a little finishing by hand. 

 Wh" can look at these different stages in the manufacture 

 of a single small portion of a watcii's mechanism and not 

 be struck with wonder at the amount of thought, industry, 

 and application bestowed upon a device for telling us how 

 far we are from midday or midnight 1 



{To he continued.) 



NERVOUS EXHAUSTION. 



By Edwin Wooton. 



(Confinvcd from x*. 430.) 



THE subjective basis common to all the phenomena of 

 complex nervous exhaustion is the occurrence of an 

 idea concerned witb a certain bodily act or mental condition 

 of the individual, which act is carried out by the latter and 

 into which mental condition he passes ; and the proximate 

 causation m.iy be briefly summed up by sayiug that the 

 controlling or volitional regions of the brain, owing to 

 physical weakness, are unable to maintain their ascendancy 

 over the body's mechanical nervous apparatus, which is 

 itself in disorder and incapable of obedience ; acid that an 

 idea of action communicated to the latter is carried out by 

 it in spite of the individual's will. 



These ideas may be classified as : {a) Fear of inability to 

 perform ; (b) Fear of involuntary performance ; (c) Mere 

 present cognition that such acts are performed. 



All these ideas have reference, (1) to muscular actions, 

 (2) to mental acts, (3) to glandular functions. 



Chief Phenomena: (1) Muscular actions: Fear of 

 inability — to speak loudly ; to swallow ; to perform any 

 customary manual or similar bodily action, as walking 

 straightly; to articulate clearly ; micturate; keep the body 

 steady or any particular part, as the head or hand ; to 

 perform many complex actions — as to look a certain indi- 

 vidual in the face, to pass a certain spot, &c. ; to keep the 

 eye and facial muscles tense and firm. Fear of involun- 

 tarily shaking the limbs ; breathing heavily ; blushing, 

 paling, or blanching ; stammering and stuttermg, speaking 

 in falsetto voice. Mere cognition of a former fear, or of the 

 act, or any of the above phenomena. 



(2) Mental actions : Fear of inability to give utterance 

 to eloquent or graceful language, maintain one's vivacity of 

 manner and repartee, recollect any fact ; fear of involun- 

 tarily calling up certain mental pictures, &c. ; mere 

 cognition of any of the above. 



('>'<) Glandular functions : Fear of inability to secrete 

 saliva ; fear of excessive salivary secretion ; mere cognition 

 of either of the above. 



These acts are all controllable b}- strong efforts of 

 volition. As they occur, however, in exhausted nervous 

 systems, the volitional efforts, except under great stimula- 

 tion, are seldom capable of controlliog any one such act. 



With regard to the " complex actions " mentioned, there 

 is no real dread of the person or place, but a particular 



mental state of perturbation having dominated the in- 

 dividual when in association with them through causes 

 very frequently totally unconnected with the latter ; when- 

 ever the patient and the objective person or place are again 

 brought into relationship the mental condition once more 

 sujiervenes ; and it is this the sufferer dreads. 



As examples, I may mention that commercial men find 

 themselves dreading to transact banking or postal business. 

 The sight of a person standing in a doorway in a street 

 through which the nervous man is journeying will impel 

 him to avoid passing such person, and he will turn back ; 

 or, if he exercise his strength of mind and continue his 

 course, will be extremely uncomfortable until he has gone 

 by the object of his unreasonable dread. 



All the mental phenomena considered are due to exhaus- 

 tion of the brain, the purely physical to that of the spinal 

 cord. 



With the incidence of chemical weakness the electric 

 and magnetic states become disturbed, and their intensity 

 decreases. The continuation of the exhausting causes 

 results in the establishment of immature physically weak 

 tissue, since, before the cells have had time to become 

 developed, energy is demanded of them, and they become 

 disintegrated, to be replaced by a still weaker material, 

 the mischief being intensified with the lapse of time until 

 the character of the brain-substance is little else than 

 embryonic. 



The chief factors in producing exhaustion both of the 

 brain and spinal cord are (1) loss of blood or vital material 

 derived therefrom, (2) insufficiency of food, (3) excess of 

 tea, coffee, alcohol, and tobacco, (4) excessive muscular 

 exertion. 



Exhaustion of the brain separately may be produced by 

 mental work, whether intellectual or mere worry. These 

 must now be briefly considered. Nos. 1 and 2 need no 

 special remark. With No. 3, however, I shall Vieed to 

 deal at length. One of the most important processes by 

 which the functions of the body are carried on is that of 

 oxidation of the tissues. The action of tea, cofl'ee, alcohol, 

 and tobacco, that is of their active principles, is to lessen 

 oxidation, and so to prevent tissue waste or destruction in 

 this particular form. But here their identity of action 

 ceases ; for while tobacco produces only the result given, 

 putting on one side absolute blood-poisoning from very 

 excessive smoking, chewing, or snuff-taking, which cases 

 are pare, tea, coffee, and alcohol stimulate the brain and 

 spinal cord, compelling them to an increase of work and 

 producing destruction of material, and its excretion in 

 manner other than by oxidation. 



If, then, prevention of the last-named process were in 

 itself beneficial, there would yet be a set-off in the other 

 modes of waste alluded to. But the benefit resulting 

 from lessened oxidation is limited ; it is, in fact, a mere 

 re.it of the tissues, and this, if pushed to an extreme, has, 

 as an inevitable sequence, tissue degeneration, since old and 

 otherwise eflfete material is made to retain its place and 

 fulfil its duties as best it may, instead of having its labours 

 completed by such oxidation, which would result in its 

 removal and its replacement by a fresh formation. 



It may be said, therefore, that while alcohol, tea, coffee, 

 and tobacco act as sedatives by arresting a certain form of 

 natural waste, the three first have, in another manner, an 

 action as stimulants. 



The laws of every human body are identical — that is, 

 physiology knows no individual variation — but the intensity 

 of such laws, or the susceptibility of the person to certain 

 influences, are in no two cases exactly equal. For this 

 reason, it is impossible to lay down a rule which shall be 

 universally applicable as to the exact amount of tobacco, 



