Nervous Influence Dr. Brown- 



I have seen convulsions stopped immediately by the 

 passage of carbonic add In that way, and the rospira- 

 tory movements themselves maj r be stopped altogether 

 for a time ; and as you are sure that, they will return if 

 you stop noting with the carbonic acid, yon have there a 

 means of diminishing the iiiilnonce of a morbid state of 

 respiration. 



There are facts which I should have mentioned re- 

 gimllnff the heart, which relate also to respiration. If 

 we take a pair of bellows and insufflate air into the 

 mouth of an animal, we find that the activ/iy of the 

 heart is diminished. If wo do the same with a view of 

 affecting the respiration, we find that the animal does 

 not then take the trouble to breathe. It seemed to the 

 physiologist that first made the experiment that, as he 

 was giving the animals all ihc air they needed, they 

 would be perfectly stupid to take the trouble to breathe. 

 [Laughter.] The reality is that they do not think at all 

 about it. I may say that they have no power of think- 

 in.?, as in many eases the activity of the tuind is lost for 

 the time. But even if the mind remains, there is a ces- 

 sation of the activity of the cells that serve respiration 

 by the irritation of nerve-fibers iu the bronchia. 

 I have ascertained for instance that if you divide the 

 par vagum .n the neck so that the communication be 

 tveeii the bronchia and the bram no longer exists, if 

 you insufflate carbonic acid into the lungs there is no 

 more stoppage of the activity. Therefore the stoppage 

 took place through the influence that was propagated in 

 the ramifications of the par vagum toward the brain. 

 As Heriug has insisted upon, there are many facts which 

 show that the very effort of breathing brings with it a 

 cause that stops breathing. The very fact of drawing 

 in air is a cause which stops the action of drawing in 

 air. He has gone a little farther than I should go in 

 saying that the expulsion of air from the lung.-; is also a 

 cause of stoppage of expiration. It seems in reality as 

 if these three movements, the movements of the heart, 

 of inspiration, and expiration, had associated with 

 them a cause that diminished them. When that cause 

 ts deficient, iu morbid states, then we find the move- 

 ments of the heart becoming exceedingly rapid, and we 

 flud the movements of respiration becoming exceed- 

 ingly rapid and tumultuous. Tae regulation of those 

 movements belongs to the proper action 

 of those powers of arrest which exist 

 there. As regards the heart, in cases 



of palpitation, for instance, we have a simple means of 

 diminishing the palpitation; it is breathing iu rapidly 

 and forcibly a good deal o,f air, dilating the chest as 

 powerfully and quickly as wt> can. In that way an in- 

 fluence is developed which I have found to be the result 

 of the association of the nerve loice that goes to the 

 muscles of the chest aurt the force which descends and 

 stops the heart's action. At the same time rhat tus cur- 

 rent goes from the brain to the muscles of the chest to. 

 dilate it a current associated with that goes down the 

 par vaffum toward the heart to diminish its action. In 

 health at every moment this thing takes place. It 

 takes piaco in a very slight degree indeed. Every act 

 of breathing is an act which moderates the action of the 

 heart. So then there is an admirable provision of nature 

 by which an excessive action finds a moderation in 

 Something which takes place usually along with it. 



MEANS OF CHECKING COUGHING, SNEEZING, &C. 



There ure many facts which show that morbid phe- 

 nomena of respiration can be also stopped by the influ- 

 ence of arrest. Coughing, for instance, can be stopped 

 by pressing on the nerves on the lip in the neiahborhood 

 Of the nose. A pressure there may prevent a cough 



when it is beginning. Sneezing may be stoopM by tho 

 same mechanism. Pressing also in the neighborhood of 

 the ear, right in front of tho car, may stop coughing. 

 It is so also of hiccough, but much less HO than for sneez- 

 ing or coughing. Pressing very hard on tho top of the 

 month inside is also a means of stopping coughing. And. 

 1 may say that the will has immense power there. There 

 was a French soldier who used to say, whenever he en- 

 tered the wards of his hospital, "The first patient who 

 coughs here will he deprived of food to-day." It was 

 exceedingly rare that a patient coughed then. 



There are many other affections associated with 

 breathing which can be stopped by the same mechan- 

 ism that stops the heart's action. In spasm of the 

 glottis, which is a terrible thing in children, as you well 

 know, as it sometimes causes death, and also in whoop- 

 ing-cough, it is possible to afford relief by throwing 

 cold water on the face, or by tickling tho soles of the 

 feet, which oroduces laughter and at the same time goes 

 to the gray matter that is producing the spasm and 

 arrests it almost at once. I would not say that, these 

 means are always successful. I would not say that we 

 can always prevent cough by our will; but iu many 

 instances those tilings are possible, and if you remember 

 that iu bronchitis and pneumonia, or anv other acute 

 affection of the lungs, hacking or couarhing greatly in- 

 creases the trouble at times, you can easily see how im- 

 portant it is for the patient to try to avoid coughing aa 

 best he can. 



There is also a series of other convulsive movements 

 more or less associated with breathing, and it is very 

 important iu those cases to counteract the influence by 

 action on certain parts. There is a form of epilepsy 

 which consists almost exclusively in what Basil Hall 

 has called laryngUnius. He had an idea that it was 

 essential to open the trachea and let the patient breathe 

 through an opening there. But this is not at all neces- 

 sary, even if it did good. Touching the larynx, with a 

 sponge charged with a solution of nitrate of silver will 

 very frequently prevent laj.yngi sinus, when it has iust 

 begun and it has very little power. But iu those cases 

 of laryngeal epilepsy, iu which the convulsions come 

 from affections caused by a spasm of the larynx, there 

 is no cioubt I hat this device or expedient changes the 

 activity iu the muscles, and that activity is enough to 

 produce a cure. 



There are a good many other phenomena of arrest. 

 The most interesting are those relating to the brain. I 

 cannot Iu this lecture speak of more than one of tnem, 

 and that is arrest of the cerebral activity, of thought, 

 of consciousness. It is well known that in epilepsy cer- 

 ebral activity is lost. It is well-known, also, that in 

 certain cases of syncope it is lost. Iu cases of sleep, 

 also, it is lost, except of course iu great dreamers, and 

 then there is hardly any consciousness, and in any case 

 the condition is quite different from that of w r akefulncss. 

 There is an evidence that- a theory which I advanced 

 long ago to explain the loss of activity iu the brain is 

 only partially true. It was that a contraction or spasm 

 takes place in the blood vessels of tho brain, that blood 

 does not circulate there auy more, and that, as I then 

 supposed, the stoppage of tho circulation causes a ces- 

 sation of the activity of the brain. But there is auother 

 cause iu these cases in which there cannot be a contrac- 

 tion of the blood vessels, because the principal nerve 

 which produces these contractions has been divided? 

 and even iu those cases a loss of consciousness can take 

 place suddenly. Pricking the base of the braia 

 may cause a complete loss of consciousness in an 

 animal after a division of the nerves that go to the 



