In the fifteenth and sixteenth centuries, a renaissance of interest in ancient culture, including esoterica, took place in Western Europe. The iatroscientiflc stage (from the Greek, «iatros», or doctor) was characterized by the appearance of a series of trends - such as iatrochemistry, iatromathematics, and iatrophysics -that developed in the medical faculties of universities. These approaches played an important transitional role in the shift toward modern science. It was not known until recently that interest in iatroscience also existed in Russia from the epoch of Ivan the Terrible until the time of Peter the Great. The recent discovery of materials on iatromathematics includes prognosticating tablets, which were used in Russia from the end of the fifteenth century to the beginning of the sixteenth century. Their application for medical purposes is confirmed by B. N. Morozov's recent finding of a codicil in an herbal from 1534, concerning auspicious days for cures. The note was added most likely in 1570 by the physician-astrologer Bomelius, the czar's doctor. The tradition of iatromathematical tablets was also reflected in the much later publication of the «Bruce calendar» at the beginning of the eighteenth century.