7,S81.] lUO [Patterson. 



full plaj-, while the physical affection, if it caused to himself some suffer- 

 ing, in no degree hindered his success. For, since a change of profession 

 had become necessary, he accepted an appointment in the Mint at Phila- 

 delphia, and thus began the life-work by which his reputation was estab- 

 lished and made firm. 



Mr. DuBois entered the Mint in September, 1833, and was first em- 

 ployed in the office of the Director, Dr. Moore. In 1835, at the request of 

 the Assayer, Mr. Jacob R. Eckfeldt, he was transferred to a more con- 

 genial position in the Assay Department. Here he continued for the re- 

 mainder of his life. In 1836 he w^as appointed Assistant Assayer. In 

 September, 1872, he succeeded Mr. Eckfeldt, as Assayer, and remained at 

 the head of the department until his death, July 14, 1881, thus completing 

 nearly forty-eight years of Mint service. 



For the special branch of metallurgy in which Mr. DuBois thus en- 

 gaged, we see that his previous training had not prepared him ; but doubt- 

 less he had been marked as having the intelligence, the carefulness and the 

 concentration of mind required for this work, and he had in Mr. Eckfeldt, 

 as instructor, a thorough master of the art. It is certain that Mr. DuBois 

 early took rank as an accomplished assayer, and long before his death had 

 reached the head of his profession. 



I have referred to the association of Mr. Eckfeldt and Mr. DuBois, and 

 it is fitting, before I proceed farther, to allude to the singular partnership 

 in the labors of these two. The close intimacy made needful by their offi- 

 cial relations, developed into warm friendship. The tie was made closer 

 by the marriage of Mr. DuBois, in 1840, to Susanna Eckfeldt, the sister of 

 his chief. I shall have to speak of published works and scientific commu- 

 nications appearing under the names of Eckfeldt and DuBois. Although it 

 was understood that Mr. DuBois was the sole literary author, yet no sepa- 

 rate claim of authorship w^as made by either. Whatever of reputation 

 was earned, each was contented that it might be shared by the other, and 

 jealousy never for a moment weakened a union that bound them for life. 



A variety of circumstances gave importance to the Assay Department of 

 the Mint during the service of Mr. DuBois. Most of these he has himself, 

 in rapid summary, and with engaging style, set before us in his obituarj' 

 notice of Mr. Eckfeldt read before this Society. Considering how inti- 

 mately he was associated with his chief in the labors of that time, the de- 

 tails thus given were in large part auto-biographical, and I shall briefly 

 recall them as appropriate to this obituary notice. 



In the year 1834, a change took place in the ratio of gold to silver in the 

 standard of U. S. coins, the effect of which w^as to bring large deposits of 

 gold to the Mint. The coinage previously had been chiefly of silver. The 

 more equal supply of the precious metals gave active employment in the 

 assay of each of them, and was of course most valuable as an experience 

 to Mr. DuBois, who about this time became connected with the Assay De- 

 partment. 



In 1837, on a revision of the Mint laws and standards brought about by 



