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Tribune Extras Lecture and Letter Scries. 



put them forward and immediately after having put 

 them forward he will say: "I know they are insane." 

 lie is p;-i -fee-fly right, perfectly rational, while at the 

 same time he is completely insane. Dr. \Vigan has con- 

 cluded, without any positive demonstration, that in 

 those east's one-halt of the brain is normal and the other 

 half is \vroni:; one-half is employed in the mental facul- 

 ties in a normal way ; the other is employed as regards 

 the mental faculties in quite a wrong way. But there 

 are cases which. are more interesting, per- 

 haps, ami which, I think, fall more clen.rly 

 under that view, that there are two brains. 

 I saw a boy. lor insrmre, at Not tin.;:! nil, in London, 

 once, who had two mental lives. In the course of the 

 day, generally at the same, time but not constantly, his 

 head was seen to f 11 suddenly. He remained erecr, 

 however, if hi- was s.'anding, or if sitting he remained in 

 his position; if talking he Bopped talking for a while; it' 

 making ti movement lie stopped moving for a while, and 

 alter one or two minutes of that state of falling for- 

 ward or drooping of the head and he appeared as 

 if falling asleep suddenly, his eyes closing immedi- 

 ately af.er that his head started up, ho opened his 

 eyes periveiiy bright, looking quite awake and 

 then asking H there was anybody in the room whom 

 he had not seen previously, who the person 

 was, and whv he was not introduced to him; 

 being all the time in that state quite different from the 

 state of wakel ulness. He had eeeu me a great many 

 times, and knew me very well. Being with him once 

 when one of those attacks occurred, lie lifted his head 

 and asked his mother, -'Who is the gentleman? Why 

 iiim't you introduce him to me?" His mother iutro- 

 duced me to him. He did not know me at all. He shook 

 hands \\ili me, and then I had a conversation with him 

 as a physk-i in may have with a patient, lu another in- 

 stance, when with him again, when he had the same 

 kind ot an attack, I found that he recognized me fully, 

 and talked nf wuat we had spoken of in our first inter- 

 view. 1 a;. ceri ained from what I witnessed in those 

 two instances, and also and chiefly, I may say, 

 from his mother, a very intelligent woman, 

 that he had two lives in reality, two mental lives, one 

 in his ordinary sta e. and another occurring after that 

 HI tack ot a kind of sleep for about a minute or two.when 

 he knew in. t him.' of what existed in his other lit'e in his 

 ordinary life; that was all a blank. Ho knew nothing 

 during t'.iat second state but what hail occurred in pre- 

 vious periods of that same condition, but he knew full 

 well a 11 that had occurred then, and his recollection of 

 e\er.\ -tiling was as perfect then as it was during his or- 

 dinary Me concerning the ordinary acts of his life. He 

 had, ilierelmv, as I have, said alreadv, two absolutely 

 disiinet in . -s, in each of which he knew every ! lung that 

 belonged to the. wakeful period of that lite, and in 

 neil her of which did he know anything of what had oc- 

 curred in Iheotlier. He remained in that slate of attack 

 for a. Jimc. which was extremely variable, lift ween one 

 and three or lour hours, and after that he fell asleep, 

 and got out of that state of mind pretty much in the 

 same way that he Ind cot into it. I have seen three 

 other eiiKcs of that kind, ami as so many have fallen 

 under the eyes "f one single medical practitioner, such 

 cases cannot be extn mely rare. 



SPEECH NOT ALTOGKTIll l: l>! ITN~DENT ON ONE SIDE 

 OF TIIK Hit A IN. 



As regards the faculty of speech, the fact that we 

 have two brains perfectly distinct, one from the other, 

 U not, pernap.-, so ciisily proved as it may be as 



the man. We well know that a lesion In on?-half of the 

 brain, the left side of the brain, will produce loss of the 

 faculty of expressing the idoas by speech ; that that be- 

 longs almost exclusively to the left side of the brair, 

 but the very fact, I may say, that the loss of the faculty 

 of expressing ideas by speech depends on a disease in 

 the left side of the brain thai fact is itself 

 a proof that the left side of the brain 

 is quite distinct from the right side of 

 the brain, that it is in fact a brain in itself as regards 

 that function of the organ we call brain. Therefore the 

 fact which is perfectly well known, that out of one 

 hundred cases In which the losr, of the faculty of 

 expressing ideas by speech existed, there is only one it 

 one in which the disease was to be found in th right side 

 of the brain that fact isextremelv important in show- 

 ing that the two sides of the brain may act independ- 

 ently one from the other. I shall have to return to this 

 by and by, as much of ruy argument depends on this 

 point. 



As regards sight, a theory has been put forward by a 

 celebrated philosopher, Dr. Wollaston of London, which 

 has been admitted by a ereat many physiologists, 

 although no one has admitted it without some reluc- 

 tance. But as there was no better theory put forward, 

 that one was received as being at least probable if not 

 demonstrated. Wollasron had the view that the right 

 side of the base of the brain is the center for sight in the 

 two right halves of the eve. The right half of the right 

 eye is of course the one to the right of it, and the right 

 half of the left eye is the one nearest to the nose. The 

 inner half I should say of the left eye and 

 the outer half of the right eye have 

 for their center, according to that view, the 

 right side of the brain and vice versa the left side of the* 

 brain would be the center for sight in the left or outer 

 half of the left eye and the inner half of the right eye. 

 There is therefore, according to that view, a condition 

 which is quite peculiar. If wo admit it for a moment 

 then we ought to find that a disease in the left of the 

 brain at the base must destroy only one half of the 

 power of sight, and objects then if s.-en are, seen in one 

 half. Suppose a man to be looked at there would bo 

 visible, if it is the left side of the brain which is atti'Cted, 

 only the right half of the body. Wollaston himself had 

 that trouble. One day trying to read the name 

 of an instrument, the barometer, ho read 

 "meier" only; the other part of the word. 

 ' baro," he could not read. Another eminent friend 

 living in France, Professor Agassiz, hail the same 

 trouble. He saw one half of certain objeits. And a 

 good many patients who are iittncted especially with 

 certain disorders of movement and wit h diabetes have 

 also that trouble, they see but one half of objects. 

 There are, therefore, cases which scorn to be in favor of 

 the view. But continuing to review what ought to 

 take place, we lind that if the disease exists only in a 

 small part of the leftside of the brain, in that portion 

 which serves to sight, we ought to ilnd that then only- 

 one half of one eye will b" ati'.-cted. There arc such 

 cases. If it is the other part of that same half of the 

 base of the brain which is alf-cted, then il is only one 

 hali in the other eye which should bo affected. There 

 are also facts of that kind. 



So that there are three kinds of facts which seem to 

 support the view of Wollaston. r.ut what of that? Wo 

 philosophers do not accept conclusions because there 

 arc facts which support them. We accept conclusions 

 when all the known facts are either lu perfect harmony 



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