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T 11 A N S A C T 1 N S 



AMERICAN PHILOSOPHICAL SOCIETY 



IT E L I ) A T P H I L A I ) E L P H I A 



FOR PROMOTING USEFUL KNOWLEDGE. 



VOL. XX.— NEW SERIES. 



PUBLISHED BY TIIM SOCIETY 



SbiUfletpkU: 



MacCalla & company inc., Printers. 



1902. 



