Philadelphia businessman and president of the Tacomy Chemical Works, he joined the Academy of Natural Sciences in 1847. In 1867, when the trustees of the building fund were making a concerted effort to get money for the new building, Charles Lennig donated to the Academy some chrome ore lands in Chester County. These were sold, but a royalty clause retained some income for the Academy besides the principle gift. These papers have one letter from Lennig advising the sale of the property to Messrs. Powers and Weightman, the original document signed by eleven Academy members for the acceptance of the donation, and various other letters and documents.