Kai tsusho ko

• Published: 1695
• Author: Nishikawa Joken
• Japanese: 華夷通商考 (Ka'i tsûshô kô)

Ka'i tsûshô kô (roughly, "Thoughts on Commerce among the Civilized and Barbarians") is a 1695 publication by Nishikawa Joken, describing lands and peoples of the world, including maps and illustrations. Joken published an expanded edition, Zôho ka'i tsûshô kô, in 1709. It is perhaps the most famous of Joken's works, and likely that with the most copies extant today; the National Diet Library catalogs nearly 150 copies in libraries across Japan.

The text was originally published in two volumes, covering the lands of China, Korea, Ryukyu, Taiwan, Southeast Asia, and Europe, and their peoples. The expanded edition covers the same topics in an expanded fashion, in five volumes.

A number of later works, such as the 1788 Ryûkyû zatsuwa by Kabô Motoyoshi, draw upon the Ka'i tsûshô kô, lifting sections for republication in these later works.

References

• Daniel Said Monteiro, "Celestial Sciences in the Works of Nishikawa Joken (1648-1724)," Historia Scientarium 29-1 (2019), 125.