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Irilvne Extras Lecture and Letter Scries. 



tbcrc, ami that for a long time after deatb. But how 

 1s It that suddenly it disappears from the nervous 

 centers, so raucli so that respiration, circulation, and all 

 voluntary and involuntary movements cease t To 

 thH qMe-tion would require no little study and 

 ^ati'Mi, and tho person making it would liavo 

 much to find that would he Interesting. Wf find, how- 

 ever, in making these experiments that we can take- 

 away the part which has been considered as the focus 

 of life, by employing certain simple precautions, 

 without destroying life. At tho College of 

 Burgeons in Ljuilon, in one of my lectur -s there, I had 

 tried to show that death in the cases rel'erre I to is im- 

 mediate. I had an animal a sruinea pi;,' on which the 

 experiment was to ho performed. In making the 

 experiment iny knife slipped and went all around the 



part, eairyini: awav mure than I h.id iut'.'iided. The pig 

 survived three or four days until my IMV, tryintr to make 

 the pig sijne.il, ilmwiie I it. [Laugater.] The vital focus, 

 eo called, di>e- not deserve the nani" ; for there arc many 

 C.tses in whim it has been destroyed, and life persists. 

 Then-tore, we eamiot look upon it as being a center for 

 vital force or nervous foree. 



T-iils leads me to examine now tho question, What are 

 the place- in production of nervous force 1 Those plans 

 of production, I may say, are as extensive as the 

 nervou- ss >tetn. Fora, longtime physiologists hud con- 

 sidered that the cells were the only parts that produced 

 nerve force. But I have ascertained and proved, and I 

 think most physiologists now admit, that nerve fibers 

 can also produce nerve force. In experiments consist- 

 ing in injecting bl iod into a limb which has been 

 separated from the body for a lone: time, I 

 iiavo ascertained tho nervous force which 

 had disappeared has been reproduced. So that 

 it is clear that nerve fibers can engender nerve force. If 

 we separate u nervous center from the nerves we find 

 that in four days the norvo has lost its powei 

 altogether. It seems, therefore, that something came 

 from the nervous center which was useful in the produc- 

 tion of forces there. But it is clear, too, that there are 

 other forces reproduced in the pare. If wo allow the 

 part to receive more blood the Injection will reproduce 

 nervous force again. I have kept a uerve alive apart 

 from the hodv for 40 hours by injecting blood in it. 

 The nerve force, even in the brain, can bo re invigorated 

 when the brain has lost all power and is separated from 

 the body. An injection of blood reproduces nerve 

 force ai;aiii mid all tho activity of tiie brain 

 when In the animal is found to be manifested. In one 

 ca-e. th.it of .1 p iiient of mine who had had a dissection 

 of a iier ve, i ho nerve continued to act simultaneously for 

 four day-, aad tho muscles to winch that nerve 

 went were ju contraction for the same length of time, 

 o \Ying to tiii- pei -iM'-nce of life and action in that nerve 

 separated trum tin- brain. A tier four days tho traus- 

 lormation which we know can take place in the nerve 

 ti>.-ne had de-iro\ed nervous activity, mid the muscles 

 then remained ijuie-i-enl, completely deprived of action. 



There i- an in ..an In the body whoso functions have 

 liccn VITV much di-ciiMPdi That organ is tho cerebel- 

 lum. In in. in if, is a very largo or^an indeed. I shall 

 not dn-cu-s us innrtioiis hen-, but I will Hay that tin-re 

 is no doubt that the cerebellum is one of the principal 



foci, one of tho principal places where ner\ou- 

 forco Is produced. In many animals the principal place 

 Is the spinal marrow. But in man tie- cerebellum Is 

 the proa i focus of the production of inrvous lorce. 



FOWLU OF OXYGEN, STKYCIINIMC, AND THE WILL. 



What LUW ia tho aK'-'Ut of yix'ductiou of nervous force 



in our blood t It is clear that blood Itself must be necr"*- 

 sary to the production of nerve force. Still for a time 

 the oxvgcn alone which Is carried by the blood mar 

 suflice. Oxygen, even when tho blool seems to have 

 iieeu taken away altogether from the part, can givet-ome 

 uerve force to tho nervous system ; but there 

 is a medicinal agent which has Immense 

 power In producing nervous results. Wheu the 

 .-pinal cord of a frog has been washed of every 

 drop of blood, when injections have been mad" of pure 

 water so as to carry away every particle of blood, if 

 strychnia is put on the spinal chord, in a very short time 

 the amount of " rcllex power," which is a manifestation 

 of nerve force, is very much greater than it was before, 

 showing that strychnia has Increased that power. This 

 is the only fact wo know, which clearly proves that a 

 medicine, putting aside oxygen, can have such a power, 

 and a power, indeed, which is very treat. 



What is tho power of our will on the nerve force t This 

 is a question which a great many patient- every day ask 

 themselves. There is no doubt that nerve foree la 

 very little under our will. It may be an admirable 

 provision of nature. It may bo that we would 

 spend it very foolishly, as wo do spend many other 

 things. Still there are many circumstances when the 

 deficiency of will power is really painful, ana in 

 patients in whom the amount of nerve force is immense. 

 I have tried to measure tho amount of uervo force in 

 a frog. I have ascertained that a frog could lift a 

 weight of 20 grammes to a point which was about a line 

 and a quarter, GOO or 700 times in an hour and a quarter. 

 This is an immense amount of nervous force, and man- 

 ifested, too, when the spinal cord was uo more re- 

 ceiving blood, when there was no more cir- 

 culation. In this case the frog was beheaded. 

 Compare this with the case of a frog 

 having its head. Tho frog with a head, after 

 a very short time, could not move at all willfully ; while 

 still tho reflex action, as we call it, an irritation of the 

 skin, determined a strong movement. There, may be, 

 therefore, in certain circumstances, an immense, amount 

 of nerve force accumulated in tho system. I would not 

 say that there is no more production immediately after 

 the cessation of circulation. Iliad not washed the ves- 

 sels. There was blood left there; still there was uol 

 much of it, and it was not charged with oxj gun after a 

 time. 



There is an Immense difference as regards the amount 

 of nervous force that remains in the system a;tcr death 

 according to many circumstances, and especially ac- 

 cording to temperature. If wo have considerably 

 diminished the temperature of animals having a great 

 heat, such as we have, and we then kill them by 

 me. ins that will not bring on convulsions and an ex- 

 penditure of force, we llnd that the amount of torce that 

 remains is considerable, and thai it will remain there a 

 very long time. In cold-blooded animals, when the tem- 

 perature is very near freezing point, the amount of 

 nerve force that remains in them for a very long time is 

 also immense, while at a high temperature the trans- 

 formation of nerve for^e into chemical force is very 

 ranld. and then the expenditure ul nerve force is total 

 after a time, which is not long. 



The principal question I have to examine in this lec- 

 ture, however, is the one I shall now spend of ; namely, 

 is there unitv of lorco or only one nerve force, or aro 

 there main' lu our system I 



I have lor a long time tried to prove that there is 

 unity of nervo force. If wo spend force, either in tho 

 way I am uow doing, by mental uiuro thau by physical 



