LIFE OF JAMES DWIGHT DANA 



during his Mediterranean voyage, he became interested 

 in this subject, as shown by his paper on Vesuvius, the 

 first he ever published, but his interest was greatly quick- 

 ened and broadened by the study of volcanic phenomena 

 in the South Seas, especially in the Hawaiian Islands. 

 In accordance with the abounding fertility of his thought, 

 he now no longer confined himself to simple local volcan- 

 ism, but connected this with all other forms of igneous 

 agency, and especially with those grander movements of 

 the earth crust which determine the greater features of 

 the earth's surface. These movements, though so slow 

 and inconspicuous as to be unperceived except by the 

 ever-watchful eye of science, yet, extending over wide 

 areas and acting through inconceivable time, their ac- 

 cumulated effects far surpass all other forms. Indeed 

 volcanic eruptions and earthquake shocks are but occa- 

 sional accidents in the slow march of these grander move- 

 ments. 



Thus it is in all things, the really most potent causes 

 are slow in operation and inconspicuous in their effects, 

 and are therefore recognized only by the scientific thinker. 

 For example, railroad accidents and steamboat disasters, 

 plague and pestilence, strike the popular imagination and 

 fill the mind with horror, while the slower but constantly 

 acting effects of dyspepsia and consumption, which de- 

 stroy their thousands for one carried off by the more 

 catastrophic way, hardly attract attention enough to en- 

 force their remedy by improved sanitary conditions. 

 Similarly wars and revolutions strike the popular im- 

 agination and fill the pages of history, while the slow 

 approaches of political corruption and decay of truthful- 

 ness which poison the life-blood and sap the vitality of 

 nations are hardly regarded. Even so volcanoes and 

 earthquakes strike the imagination and fill the pages of 

 geological literature, while the slowly accumulating and 

 far grander effects of crust oscillations hardly arrest at- 



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