Hare we Tivo Brains ? ly Dr. Brown- Sfyuard. 



33 



see, has the rower of this one, and in all perhaps it 

 might have had if the proper development bad taken 

 place ; but this other serves contrarily to the first one. 

 The right side of the brain serves chiefly to emotional 

 manifestations, hysterical manifestations included, and 

 to the needs of the nutrition of the body in various 

 parts. There is, therefore, taking a large view of the 

 differences between the two brains, this difference, that 

 one of them the left serves to what wo call t'.io 

 life of relation, while the right serves to what 

 we call the organic life. This view, which I 

 had put forward already five or six years ago, 

 has begun now to receive demonstration from several 

 physicians, and I am therefore the more emboldened in 

 maintaining the correctness of that view of mine. The 

 right side of the brain is remarkable in producing 

 alterations of nutrition either in limbs that are 

 paralyzed, or in the back. It is perfectly well-known 

 that a number of patients die every month in every 

 large city of ulcerations taking place orU the nates or on 

 the sacrum coming from an irritation of the brain. 

 Tliese patients are more numerous among those 

 attacked by disease in the right side of the 

 brain than among those attacked with disease in 

 the left side of the braiu. Either codenia or 

 jed sores, either one or the other of those 

 ITVO kinds of ulceration is more frequent in 

 cases of disease of the right side of the brain than in 

 cases of the left side. The proportion is considerable. 

 It is as two-thirds for the right side of the brain and 

 one-third for the left. There are many other points 

 which show the same thing. An ulceration in the lungs, 

 an ulceration in the liver, a hemorrhage for instance 

 and sudden inflammation all these disturbances can 

 take place under an irritation of the brain as I have 

 shown; butintheso cases it is chiefly the right side of 

 the brain that has the power. 



I have already said that hysterical and emotional 

 symptoms are more common in cases of disease of the 

 right side of the brain. This has been established 

 already bv a good many physicians Drs. Brequet and 

 Du Floret and a good many others, and myself. We 

 have collected cases of paralysis in one-half of tlie body, 

 caused by hysteria, and this proporiiou has been found ; 

 but of 121 cases of paralysis caused by hysteria (a paral- 

 ysis which is usually merely transient, and very rarely 

 lasts long) in 121 of these cases there was disease of the 

 brain on the right side 97 times, and disease on the left 

 24 times; so that the right side predominates in this 

 class of affections. That paralysis exists on the left side 

 of the body more frequently than on the right side you 

 well know, and, as it affects chiefly the right side of the 

 brain, it affects chiefly the left side of the body. 



SIDES OF THE BRAIN UNEQUALLY DEVELOPED. 



Now as regards other points, my pupil, Dr. Jackson, 

 has ascertained that an inflammation of the retina pro- 

 duces amaurosis more frequently In both eyes from dis- 

 ease of the right side of the brain than the lefi side. 

 Convulsions of the eye take place very frequently in 

 cases of disease of the brain. I have ascertained in 

 taking up the cases published by Dr. Prevost, Dr. Char- 

 inel, and many others and myself I have ascertained 

 that out of 69 cases in which these convulsions of the eye 

 occurred there were 47 due to the disease in the right 

 side of the brain, and 22 due to disease in the left side ot 

 the brain. Therefore there is a great difference between 

 che two sides of the brain as you will see. It Is so as 

 regards general convulsions. Collender and myself have 

 euowii that general convulsions will occur much more 



frequently in cases of disease of the right side of tho 

 brain than in cases of disease of 11m left side. I have 

 ascertained that both will occur far more frequently 

 in cases of disease of the right side of the Vain than In 

 casus of disease of the. same extent and 'he same location 

 in tho left side of the brain. Not only disease, in tho 

 right side of the brain wdl havo the greatest power in 

 that respect, but it will ai*n. if tne, patient do m not die, 

 produce a more marked paralysis; it will produce, also, 

 a more extensive paralysis and a more durable one. So 

 that, as regards degree, as regards extent, a.s regards 

 duration of the paralysis, the right side of the brain Is, 

 by far. worse than tho left, showing again that that side 

 bus the greater power of nutrition. There are a good 

 many other points showing a difference of the samo 

 kind. I pass them over, as time presses. There n, 

 therefore, as you will see, a radical difference l>- ween 

 these sides of the brain. But now this depends, as I 

 have said already, not upon the fact that tho two si 1 n 

 of the brain are very different originally, but it depends 

 on development. Every organ which is put in use lor a 

 certain function gets developed, and more apt t'i per- 

 form that function. Indeed the organ in size shows it. 

 The left side of the brain, which is used most, in our 

 system, is larger thau the right side of the brain. Tho 

 left side of the brain besides receives a groat deal more 

 ulood than the right side of tae brain, because it lias a 

 preponderance in our system, and every organ that acts 

 much, receives more blood. As regards the influ- 

 ence of action on the brain, there is a fact which 

 iiatters know very well. If a parson is accuscome.1 for 

 many, many years from adult life say from 20 up to 40 

 or more to go to tlie same halter, the hatter 

 will find after a time that he has to enlarge the 

 hat of his customer; and, indeed, a person advanced in 

 life, even having passed 56, as your lecturer has, has a 

 chance to observe such a change. There is no period of 

 six months that lias passed that I have not found that 

 my hat, Lf neglected and put aside, became too sm.ill. 

 The head, therefore, growing, is very strong proof th it 

 the brain grows also. Action, therefore, is a means of 

 increasing size, is a moans of development; aud 

 I have no doubt that a good mauy among you 

 have observed that after they pay great attention 

 to a subject, they have not oaly acquired knowledge on 

 that subject, but become much more able to solve q.ues- 

 tions relating to tbat subject that they have developed 

 the part of the brain which has been used for tho acts 

 that they have performed, aud that part has become 

 far more able to perform its functions. This is perfectly 

 well shown by every tlimar in our system. We well know 

 what a power a pianist can have, if that piauUt con- 

 tinues to exercise his fingers and braiu on the piano. But 

 such a pianist neglecting to perform the acts that he 

 was accustomed to perform before, it is very eoou found 

 that there Is a defect. We must go on, therefor,', exer- 

 cising the organs in which we desire to havo the great 

 activity of life. There la no doubt, therefore, that the 

 left side of the brain, as is shown by its great enlarge- 

 ment compared with the nglu side, and as is shown also 

 by the quantity of blood that it receives, that organ is 

 the one which is predominant in our system. But our 

 being right-handed, shows it also. 



RIGHT-HANDEDNESS NATURAL TO MEN AND ANIMALS. 



It is quite certain that right-handedntsa depends 

 something on nature. As you well know, the wildest 

 populations in the world are right-handed, as we are. 

 There is no population anywhere in tho world that has 

 act been found rigut-hauded. There is therefore in mail 



