National Academy of Sciences. 



THREE NOTABLE ESSAYS SECOND DAY. 

 DR. BUOWN-SEQUAKD'S THEORY OF THE OPERATION 

 OF THE NERVES AND BRAIN PROF. NEWCOMB 

 TELLS OF WHAT AMERICA IS DOING FOR THE 

 COMING TRANSIT OF VENUS MAJOR POWELL'S 

 EXPLORATION OF THE CANONS OF COM IKADO. 

 WASHINGTON, April 22. The session of this day far 

 exceeded its predecessor in interest. It is rather un- 

 fortunate that the Academy makes no announce- 

 ment in advance of the programme for the day, but 

 this is of a piece with its general indifference to 

 public attention. Not only is no programme pub- 

 lished, but scarcely any is arranged in advance. 

 Only a few of its members knew that Dr. 

 Brown-Se~quard was to deliver an address; 

 still fewer knew that Prof. Newcomb was to speak, 

 and there was an element of uncertainty even as to 

 Major Powell. Had it been generally known that 

 Dr. Brown-Sequard would tell us something about 

 our brains, there would have been no difficulty in 

 packing the long hall of the Smithsonian with an 

 eager audience. A master of a subject with which 

 few are acquainted, he brings to every utterance 

 upon it the rare results of his own inquiries 

 coupled Avitli a freedom from prejudice in favor 

 of antiquated views that is rare in his profession. 

 In this address he gave a clearer expression 

 than ever before to his own views of the struc- 

 ture and functions of the brain and nervous 

 system. Hitherto his lectures seem to have been too 

 much confined to tearing down the edifices of theory 

 which bis predecessors have so laboriously reared. 

 The present address is not open to that objection, 

 though it does good service in exposing the fallacy 

 of views recently advanced by Dr. Ferrier of En- 

 gland, formed on a narrow circle o experiments, 

 which have threatened to lead us back into the 

 mists of error from which we were gradually emerg- 

 ing. 



The address of Prof. Simon Newcomb, the emi- 

 nent astronomer of the Washington Observatory, 

 has an immediate iutarest. Very recently The Lon- 

 don Tinies, in a very long article describing the 

 preparations making for observations on the transit 

 of Venus, dismissed those of America in a sentence 

 of almost contemptuous brevity, to the etreat that 

 little or nothing was known about them. It is a 

 fact that our preparations are of the most thorough 

 character, that they embrace novel and ingenious 

 modesof procedure, that they are worthy both in 

 their scale and character of the nation and of Amer- 

 ican science, and that they bid fair to accomplish 

 excellent results. It was to tell of this that Prof. 

 Newcomb emerged from the ceclusion of his watch- 

 tower in the skies a man of bashful and retiring 

 manner, plain and thoughtful in his words, and giv- 

 ing his facts with simple directness of expression. 

 Both Prof. Newcomb and Dr. Browii-Sdquard speak 

 without notes, and do not prepare their communica- 

 tions in manuscript. 



Major Powell's description of the Canons of Colo- 

 rado brings freshly before us the wild features of 

 that strange Western country which ho has done so 

 much to explore. His expedition seerns to have 



penetrated regions hitherto deemed almost inac- 

 cessible, and ho has brought back a large amount of 

 information of value, from a scientific point of view, 

 as well as an exceedingly entertaining narrative of 

 adventure. 



Notwithstanding the fact that so few knew what 

 was in store for them, there was a considerable 

 popular audience present at the session, including a 

 number of ladies. 



FUNCTIONS OF THE BRAIN AND NERVES. 



BY DR. C. E. BROWN-SEQUAUD. 



The title of this address was " On the Pre- 

 tended Localization of the Mo.ntiil and the 8'Msorial 

 Functions of the Brain." Dr. Brown-Se'cniard brg:ni hy 

 saying that the subject lias been rendered morn di.'licult 

 by assumptions of physiologists upon iusuthVient dat;t. 

 Among the views which have been recently put forward 

 unon the localization of nervous power m certain 

 parts of the brain, there are two of importance: 

 One relates to the seat of power actuating 

 muscles, aud the other is as to the seat of 

 sensation for different nerves. In the latter partieular, 

 I shall review especially the assumption in respect to 

 the scat of power for speech. The folio-wing an- some 

 of the old views respecting the localization m the braiu 

 of tne various faculties. There was a theory put for- 

 ward by Miiller of Berlin which for a time had great 

 popularity. It was, however, absolutely wrong. It 

 assumed that as regards the power of tho action of 

 the will on the muscles, the brain must 

 be considered as the keys of a piano. When 

 the soul or the will acted to produce a movement, it was 

 supposed to act upou the nerves as the fingers upon tho 

 keys of a piano. As regards sensation, the mechanism 

 was supposed to DH equally simple; It was supposed 

 that there were elements by which the sensations were 

 transmitted through the whole system, without any 

 break, through I he spiral cord to the brain. 



DEFECTS OF ^TIIE MECHANICAL THEORY OF THE 

 NERVES. 



This theory assumed that sensation was conveyed 

 through tho body by the nerves, as the bells rung in 

 any part of a hotel have the sound conveyed along 

 wires to a central office, where the fact is recognized 

 from where the call may come. But this assumption 

 was just as false as it was simple. There is no su<-h com- 

 pact continuity. Pathology shosvs that there is no foun- 

 dation for such views. la tho first place, tho 

 spinal eord (which is the organ through which 

 all tlin nerve fibers or conductors coming through 

 the brain have to pass and also all the conductors com- 

 ing from the periphery to the brain have to pass) ran 

 be destroyed iu great part without destroying tiller 

 the power of motion or the power cf receiving sensa- 

 tions. There are facts respecting tho meclnlln o'ulon- 

 gata, which as you know is between the brain ami tho 

 spinal cord, which place this beyond the reach of qne-i- 

 tion, and prevent MitUer's theory of mechanism from 

 having our permanen* acceptance. 



There are other facts relating to this question whicli 

 are certainly quite clear. Tliero are animals utterly 

 without brain, which still exercise the functions that are 

 supposed to be locate, I in that organ, such for instance 

 as the Aii>hinjnis ImnT'iliitnx. In others we find the 

 part that answers to tho braiu is hardly large enough 

 to meet the requirements of such an organ. 

 Now if you hold your arm upon a table 

 aud try to make dots with a pencil In your 



