SCIENTIFIC CORRESPONDENCE 



IN the following pages a considerable number of letters will 

 be brought together, partly as illustrations of Dana's activity 

 interesting to those who knew him and who will willingly trace 

 from year to year the progress of his studies ; partly as indica- 

 tions of the difficulties encountered by a scientific man of the 

 last generation, and of the way in which they were met. 



I shall first give the letters of Gray, Darwin, Agassiz, Guyot, 

 and Geikie, for the correspondence with these men ran over a 

 long term of years; and afterwards a few letters will be added 

 from occasional correspondents. 



I 



CORRESPONDENCE WITH DR. ASA GRAY 



His prolonged intimacy with the illustrious botanist of 

 Cambridge was one of the greatest intellectual pleasures 

 of Dana's life. They were kindred natures devoted to 

 kindred studies. Gray was but three years the senior, 

 and in early life this may have given him a slight degree 

 of authority. Subsequently there was nothing but reci- 

 procity. The reader has already learned that it was he 

 who persuaded Dana to go on the expedition, and after 

 its return his advice in matters pertaining to the publica- 

 tion of the reports was of the greatest value. He had 

 incisive ways of expressing his opinions, clear judgment, 

 and abundant knowledge, so that he was a most excellent 

 counsellor. Besides, he was a professor in Harvard, 

 an active member of the American Academy, and a 



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