SKETCH OF SAMUEL LUTHER DANA. 695 



"While these varied applications of science to most useful 

 purposes were daily occupations," says Dr. Hayes, " he was pur- 

 suing in his laboratory the great study of his life madder, its 

 products and its application to dyeing year after year. He 

 deemed the subject exhaustless, and while following the published 

 results of other laborers in the same field as test trials, I happen 

 to know that the most important discoveries, from time to time, 

 were made by him, and often applied, before their publication by 

 others. 



"The laboratory, in most busy moments, was exceptionally 

 neat; the deft handling of the apparatus and order of experi- 

 ments expressed the system of thought." 



Soon after removing to Lowell, Dr. Dana became interested 

 in the action of lead upon water, and made a report to the City 

 Council of that city on the danger arising from the use of lead 

 water pipes. His translation and systematic arrangement of the 

 treatise of Tanquerel on Lead Diseases was considered an impor- 

 tant contribution to medical knowledge. The discussion of the 

 lead-pipe question gave rise to several pamphlets from Dr. 

 Dana's pen. 



Another division of chemistry in which Dr. Dana did valuable 

 work was its application to agriculture. As the outcome of a 

 comprehensive series of experiments and observations, he pub- 

 lished, in 1842, The Farmer's Muck Manual of Manures, which 

 was the sheet anchor of libraries in the rural districts of New 

 England for many years. The next year an Essay on Manures 

 submitted by him won the prize offered by the Massachusetts 

 Agricultural Society. He carried into his agricultural investiga- 

 tions the same scientific methods that he had found so important 

 to success in other technical inquiries, and added an overflowing 

 love for the pursuit in all its varied bearings. The younger Silli- 

 man wrote of him : " In point of time, originality, and ability, Dr. 

 Dana stood deservedly first among scientific writers on agricul- 

 ture in the United States." 



The fourth edition of the Muck Manual was published in 1855. 

 Its preface states that "the author is not an agriculturist; he 

 does not assume the name even of agricultural chemist," and 

 mentions his position at the works of the Merrimac Company. 

 "While pursuing there," it continues, "during the years 1835, 

 1836, and 1837, researches on the action of cow dung in calico 

 dyeing, he pushed his inquiries, as a recreation, during his few 

 leisure hours, into the nature and action of manures and of soil. 

 Conversation on these matters with the geological surveyor, and 

 with the agricultural commissioner of Massachusetts, led to a 

 correspondence between the parties, which partly appeared in the 

 published reports on the geology and agriculture of Massachu- 



