Marcus Fabius Calvus, a humanist from Ravenna, first attributed the brief treatise entitled De Asse to the famous land-surveyor Balbus.  He included this work in his Latin translation of the Corpus Hippocraticum, which is now contained in a manuscript that Calvus himself donated to the Vatican Library in March 1516 (Vat. Lat. 4416).  Lachmann and Mommsen followed the humanist in accepting this attribution, but already the scholar Johann Friedrich Christ in the 18^th c. expressed doubts and proposed a later dating between 3^rd and 4^th c.  Today this view is commonly accepted both for linguistic reasons and because the text mentions a type of coinage (the tremissis, a gold coin valued at one third of a gold solidus), which only began to circulate under Severus Alexander.  [A. Borgna; tr. C. L. Caterine].