JPL Logo JPL Presents


Kats, Ṭoviyah, Ephraim Deinard, and Jacob H. Schiff. Maʻaśeh Ṭoviyah.

Venice : Nella Stamparia Bragadina. 1707.

Toviyah Kats Cohen. 1652?-1729.

This copy of the original edition of Ma’aseh is one of only a handful existing worldwide. It was the first modern Hebrew science and medical textbook encyclopedia, the first to include illustrations, and the first written for a Jewish audience.  

Cohn was born in Metz (Germany). Raised traditionally in Cracow, he intended to study medicine in Germany. As Jewish medical students routinely faced accusations of evil intentions, Cohn obtained his degree in Italy instead. He became a court physician in Turkey then wrote Ma’aseh. After retiring, he moved to Jerusalem and studied the Torah until his death.

Ma’aseh concentrates on medicine, astronomy and other disciplines. Cohn drew parallels between these ‘new sciences’ and traditional Jewish views to make his ideas more accessible to Jewish readers.  For example, Biblical themes likely helped inspire Cohn to envision the pathology illustration, titled “Dr. Cohn’s New House”.

Ma’aseh became immensely popular, and was printed 5 times in Venice between 1708 and 1850. The “House” image alone would be copied repeatedly in other books.