?8 MEMORIAL OF JOSEPH HENRY. 



trust committed to him by the Government of the country. Surely 

 it is largely due to the services which Joseph Henry rendered 

 to mankind by his scientific discoveries and researches. Let the 

 philosopher be ever so great in the administration of affairs, even 

 though these connect themselves directly with the increase and 

 spread of knowledge among men, yet the merit and the glory of 

 the discovery of great scientific truths transcend the honors of any 

 merely administrative success. This occasion then rises to the 

 height of a national recognition of science for its own sake in 

 enlarging the sphere of human intelligence, as well as for its pro- 

 motion of the material welfare of mankind, and I do not doubt 

 that the knowledge of what we are this night doing will every- 

 where give to men of science a new incentive to labor, and will 

 win for our country an added claim to the honors of an advancing 

 civilization. 



That first year of the century which brought to view the electric 

 properties of the voltaic apparatus opened an active campaign in 

 this department of research among the physicists and chemists of 

 Europe. Within a i\j\v months of the announcement of the electric 

 polarity and the physiological effects of the voltaic pile, Nichol- 

 son and ('aim. isle, of England, discovered that its polar wires 

 had the property, in transmitting the current, of decomposing 

 water, and gathering its elements at opposite extremities; and soon 

 with improved forms of the apparatus its marvelous analytic power 

 was brought to bear on other liquids and solutions, until, through 

 the labors mainly of Berzelttjs and of Daw, the great generali- 

 zation of electro-positive and electro-negative substances was estab- 

 lished, and with it the fruitful theory of the electro-chemical com- 

 position of compound bodies. 



Greater among the active investigators of this period was Davy, 

 who, but a few years before an apothecary's apprentice, was now 

 seen, inspired by the enthusiasm of an ardent genius, applying the 



