SAMUEL LUTHER DANA. 



317 



Manure. What second ? Manure. What third ? Manure. 

 These answers are to be united. Action and manure are the 

 first and last requisites in agriculture ; and in the attempt to 

 show what is the last, and how it acts, will be offered every in- 

 ducement to action." 



In the seventy-five pages of this chapter he describes the 

 action of the manures of all domestic animals, also poudrette 

 and certain waste materials valuable as fertilizers wool wash- 

 ings, soot, bones, and spent lye from soapworks and gives the 

 chemical composition of nearly all. 



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 prop- 

 erties 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 in- 

 creased by constant additions from the best and latest authori- 

 ties. It aided him greatly in his agricultural researches. One 

 of his courteous attentions to scientific visitors was an excur- 

 sion to a travelling 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 u, 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 hu- 

 mour had some scope, and added a charm and zest to his 

 descriptions that made them highly enjoyable and utterly in- 

 imitable. 



Dr. Dana's first wife died in 1828 and he afterward 



