SKETCH OF SAMUEL LUTHER DA¥A. 693 



enthusiasm. They often made excursions together on foot through 

 the country lying within thirty miles around Boston for the pur- 

 pose of examining its geological structure and collecting mineral- 

 ogical specimens. The result of these researches was a volume 

 on the Mineralogy and Geology of Boston and its Vicinity, pub- 

 lished by the brothers about the time they completed their med- 

 ical studies. 



The younger brother also employed himself upon these ex- 

 cursions in searching for entomological specimens, and formed 

 quite a large collection of beautifully prepared insects. This was 

 afterward given to the Linnsean Society of New England, of 

 which the brothers, if not the founders, were among the earliest 

 members. Another taste which formed a strong bond of union 

 between them was their love of music. In college they belonged 

 to the same musical societies. 



On graduating from college Samuel began reading law with 

 his uncle, Judge Samuel Dana, then residing in Charlestown, 

 Mass. The War of 1812 was in progress, and young Dana caught 

 the prevailing military spirit. He applied for a cadetship at 

 West Point, but received instead a commission as first lieutenant 

 in the First United States Artillery, with which corps he served 

 in New York and Virginia until the close of the war. In June, 

 1815, the army was disbanded and Dana resigned his commission. 



A younger brother, Nathaniel G. Dana, was a cadet at West 

 Point during the War of 1812, graduating in 1814. He remained 

 in military life until his death in 1833. 



Samuel did not return to the law, but took up the study of 

 medicine under Dr. Bancroft, of Groton. Receiving his medical 

 degree in 1818, he began the practice of his profession in Glouces- 

 ter, Mass. The next year he married Ann Theodora, daughter 

 of Eev. Joseph Willard, D. D., who had been President of Har- 

 vard College from 1781 till his death in 1804. 



Dr. Dana now took up his abode in Walthara, Mass., where he 

 practiced medicine until 1826. Toward the close of this period 

 he established a laboratory for the production of sulphuric acid 

 and bleaching salts. This enterprise soon developed into the 

 Newton Chemical Company, of which he was chemist till 1834. 

 His friend Dr. A. A. Hayes, in the memorial pamphlet of the 

 Dana family, has testified to his wide knowledge of the proper- 

 ties of substances and his great fertility in original devices for 

 general and technological work. In his manufacture of acids 

 and other chemicals improved plans and processes were early em- 

 ployed, and Dr. Hayes mentions especially Dana's device for 

 deoxidizing manganic oxide by heating it with sulphur in order 

 to form from it (with pyroligneous acid) a crude manganous ace- 

 tate, then largely used in dyeing a fast brown. 



