From Li Baojia's late-Qing satirical novel
《官场现形记》 (Exposé of Officialdom, 1903-1905), chapter 31, which used the variant
中外合璧 to mock the clumsy mixing of Chinese and foreign military uniforms.
璧 is a circular jade with a hole; when two halves fit together perfectly, they form a
合璧 - the metaphor for a successful fusion.