In a chapter on artificial manures and irrigation, he deals with the use of swamp muck or peat, and tells how to make it a first-class fertilizer by the addition of soda ash or potash. There are a few pages on the physical properties of soils, and then the use of bones as a fertilizer is discussed. An appendix contains the results obtained by Dr. Andrew Nichols and others with the methods suggested by Dr. Dana.
Dr. Dana's geological knowledge was kept bright and increased by constant additions from the best and latest authorities. It aided him greatly in his agricultural researches. One of his courteous attentions to scientific visitors was an excursion to a traveling sand, in an outlying part of the city of Lowell, which was slowly and steadily advancing over arable land, converting it into a desert place. His long-sustained and minute observations threw strong light on the formation of sedimentary rock deposits, where currents of air rather than currents of water were the active agent, and made this field his own.
Dr. Dana died at his residence in Lowell, March 11, 1868, in consequence of a fall upon the ice at his own doorstep. In person he was tall and slender, with blue eyes, dark-brown hair, and a fair complexion. The expression of his countenance was intellectual and sympathetic. He was extremely witty, and, in his hours of relaxation from study, he entered with great zest into the pleasures of society, contributing his full share to the enjoyment of others. Even in his scientific writings his humor had some scope, and added a charm and zest to his descriptions that made them highly enjoyable and utterly inimitable.
Dr. Dana's first wife died in 1828 and he afterward married her sister. Miss Augusta Willard. James Jackson, the only son of Dr. Dana who survived childhood, when arrived at a suitable age received a commission in the United States army, and was afterward promoted to the rank of brigadier general. Dr. Dana also left three daughters.
