592 BARON VON HELMHOLTZ. 



This IS not the place for a critical estimate of Brown-Sequard's 

 work, or au enumeration of his comniunicatious. The works by 

 which he will be longest remembered are, perhaps, first, the investi* 

 gations already referred to with regai'd to the sensory tracts in the 

 spinal cord ; secondly, his insistence on the complex nature of the cere- 

 bral functions, and the interaction of one pan on another, leading to 

 the phenomena of inhibition and reinforcement ; thirdly, his studies 

 on experimental epilepsy ; fourthly, his observation that many of the 

 organs of the body, such as the suprarenal capsules and other glands, 

 both ductless and secretive, exercise an important influence on the 

 nutrition of the body through the substances which they pour into the 

 blood. These are all still living problems, and the work which he 

 did on the last of them, though it has led to much adverse criticism, 

 partly just, partly unjust, has borne and will bear practical fruit. 



It is true that in collecting materials for the support of the conclu- 

 sions which he reached he sometimes showed a lack of critical judg- 

 ment which carried him too far, and impaired the weight of his au- 

 thority in the eyes of many persons who were not in a position to know 

 the real merit of his work, and to select the grain from the chaff. It 

 is likewise true, however, that his researches gave birth to a sjjlendid 

 array of observations and generalizations, for which his name will be 

 gratefully remembered by every sincere student of physiology. 



His friend and co-worker Gley says of him, " Brown-Sequard was 

 one of the greatest discoverers of facts that the world has ever seen." 



1895. James Jackson Putnam. 



HERMANN LUDWIG FERDINAND VON HELMHOLTZ. 



Hermann Ludwig Ferdinand von Helmholtz, one of the most 

 illustrious of European savants and one of the most distinguished of 

 the Foreign Honorary Members of the American Academy of Arts 

 and Sciences, was born at Potsdam, Prussia, on August 31, 1821. 



Admitted at the age of seventeen to the Royal Military School at 

 Berlin, he became Assistant Surgeon at La Charite Hospital, and 

 later, as full Military Surgeon, was stationed at Potsdam. But after 

 four years of service he relinquished the practice of medicine to enter 

 upon congenial pursuits in extended and accurate mathematical and 

 physiological researches, and in untiring investigations of various 

 intricate questions in physics and optics. 



One of the earliest of his published scientific papers, " On the Con- 



