12 The Academy of Natural Sciences 



The death of William Maclure 5 on the 23d of March, 1840, 

 inflicted on the society the greatest loss it had yet sustained. In 

 addition to his large pecuniary contributions, he had given in 1835 

 a selection from his library in New Harmony. The transfer of the 

 collection, amounting to 2,259 volumes and an extensive series of 

 maps and charts, had been safely accomplished by Charles Pickering, 

 the distinguished author of the Chronological History of Plants, who 

 was Librarian of the Academy from 1829 to 1833. He had also con- 

 ducted the transfer and arrangement of a great number of plants 

 bequeathed by the Rev. Lewis David von Schweinitz, who died in 

 1834. 



Mr. Maclure was succeeded in the Presidency by William 

 Hembel 6 who had been elected a member in 1825. He held the 

 office from December, 1840, until December, 1849. His adminis- 

 tration was uneventful. In the hope of being able to remedy 

 impaired hearing resulting from an attack of scarlet fever he had 

 studied medicine in the University of Pennsylvania but did not 

 graduate. 



Dr. Morton announced to the meeting held June 16, 1840, that a 

 bill for the perpetual exemption of the property of the Academy 

 from taxation had passed both houses of the Legislature. 



The first annual election in the new building at Broad and San- 

 som Streets resulted as follows: President, William Hembel; 

 Vice-Presidents, John Price Wetherill, Samuel Geo. Morton, M.D. ; 

 Corresponding Secretary, Eobert Bridges, M.D.; Recording Secre- 

 tary, A. Denman Chaloner, M.D. ; Librarian, A. L. Elwyn, M.D. ; 

 Curators, William S. Vaux, John S. Phillips, Eobert Pearsall, 

 George C. Leib, M.D. 



In March, 1841, the publication of the Proceedings was com- 

 menced. The sessions of the Academy were then and until May, 

 1903, held every Tuesday evening throughout the year. 



A most important event in the history of the society was the 

 election to membership on July 29, 1845, of Dr. Joseph Leidy. He 

 published the first of a brilliant series of contributions to natural 

 history in the Proceedings a couple of months later and for the 

 succeeding forty-six years he exerted a most active influence on the 

 well-being of the institution in every department of its administra- 



5 A Memoir of William Maclure, by Samuel George Morton, M.D. 

 Published by the Academy, 1841. 



6 Simpson's Lives of Eminent Philadelphians, 1859, p. 515. 



