Subject: Chemistry

A one-page letter written by Jacob Green, Professor of Chemistry at Jefferson Medical College, to Dr. J.J. Cohen on April 4, 1837. From Philadelphia, Pennsylvania, Green discusses returning fossils to Cohen that were used in a paper presented at the Academy of Natural Sciences in Philadelphia on January 24, 1837. He also mentions sending a copy of his speech later.

A one-page stampless letter dated December 11, 1838, from Dr. Jacob Green in Philadelphia, Pennsylvania, to Dr. J. J. Cohen in Baltimore, Maryland. Green, Professor of Chemistry at Jefferson Medical College, thanks Cohen for sending fossils he examined.