1877] WRITINGS OF JOSEPH HENRY. 515 



to have at least a high appreciation of science, some famil- 

 iarity with its principles, and capability of doing something 

 in the way of promoting the objects of the association. 



The general mental qualification necessary for scientific 

 advancement is that which is usually denominated " common 

 sense;" though added to this, imagination, invention, and 

 trained logic— either of common language or of mathematics, 

 are important adjuncts. Nor are objects of scientific culture 

 difficult of attainment. It has been truly said that the " seeds 

 of great discoveries are constantly floating around us, but that 

 they only take root and germinate in minds well prepared to 

 receive them." 



The preparation however is not difficult, and many pos- 

 sess the requisites in an eminent degree who are not aware 

 of the fact. Genius itself has been defined as a mind of gen- 

 eral powers, determined — enthusiastically it may be, on one 

 pursuit. 



The method of discovery or of scientific observation is not 

 difficult. There is a story in a work entitled "Evenings at 

 Home" which produced an indelible impression on my 

 mind. It is entitled "Eyes and No Eyes," and related to 

 two boys who started on a walk during a warm summer 

 afternoon. On their return one was fatigued, dissatisfied, 

 having seen nothing, encountered only dust and heat; while 

 the other was charmed with his walk, which had been over 

 the same ground, and gave a glowing account of the objects 

 with which he had met and of the reflections which were 

 awakened b}^ them. On this story De la Beche has founded 

 a work, entitled " How to Observe in Geology," which I would 

 commend to the attention of every member of this society, 

 while I suggest that good service would be done to the ad- 

 vance of knowledge were a similar work published relative 

 to all branches of science. 



Method of Scientific Investigation. — The first requisite for an 

 observer is that his mind should be actively awakened to the 

 phenomena of nature with which he is surrounded. Thou- 

 sands of persons of excellent mental capacity pass through 

 the world without giving the slightest attention to the ever 



