Written by William Ridgeway and published in 1892, this academic study investigates the beginnings of metallic currency and weight standards using the comparative method. The author applies this approach to uncover new principles regarding monetary systems, expanding the scope beyond the traditional focus of numismatists and metrologists on Lydia, Greece, Italy, Babylon, Egypt, and Rome. The work also examines the distribution and early discovery of gold, and critiques the principles of linguistic palaeontology.