Creator
John Ayrton Paris, M.D.
Title
Pharmacologia.
Coverage
New York:
Publisher
F. & R. Lockwood,
Date
1824.
Description
This volvelle allows a physician to determine equivalent doses of medication ingredients. A volvelle, used since the 13th century, was especially helpful in science, astronomy, and mathematics, where they were often attached to an endpaper and aggregated groups of information.
Source
Collection of Ellen G. K. Rubin.