1895.] NATURAL SCIENCES OF PHILADELPHIA. 455 



contribution to the latter being specimens of Chiton, supposed to be 

 new species, from Chapman's Island. 



It was probably during this period that he prepared the text- 

 books of natural history which subsequently appeared under the 

 following titles: — 



Physiology and Animal Mechanism, 1841. 



Mammalogy. Natural History of Mammiferous Animals. 2nd 

 Hook of Natural History, 1842. 



Mollusca. Elements of Conchology, 1843. 



These works were from the text of Milne Edwards and Achille 

 Compte, and were the first of a promised series which was not, how- 

 ever, continued. 



A Lexicon of Terms in Natural History, 1850. 



Elements of Natural History, embracing Zoology, Botany, and 

 Geology. Two volumes, 1850. 



More than one member of the Academy has acknowledged his in- 

 debtedness to these text-books for his first knowledge of natural 

 history. They are purely technical and possess no literary grace 

 other than that of clearness and directness of statement. 



He served at the Naval Hospital, Brooklyn, from 1<S43 to 1847, 

 and while there organized the Naval Laboratory for supplying the 

 service with pure drugs and reliable instruments. This establish- 

 ment is said by his contemporaries to have been much needed and 

 to have especially proven its usefulness during the trying period of 

 the civil war. About this time he published a number of pamphlets 

 on the relations of the medical corps to the United States Navy with 

 a view to securing proper definition of authority, rank, responsibility, 

 etc. 



He was again Fleet Surgeon of the East India Squadron from 

 1847 to 1850. Some of his observations during this cruise were 

 embodied in a series of papers contributed to the Southern Literary 

 Messenger for 1852 and 1853. They were issued later in book-form 

 under the title " Notes and Commentaries during a Voyage to Brazil 

 and China in the year 1848." As might be expected from the 

 mode of publication, the work has not the sustained interest or value 

 of his other volumes of travel. It is discursive and disjointed, 

 although still bright and instructive. 



On his return to America he was assigned to duty in Philadelphia, 

 and immediately resumed his active connection with the Academy. 



