Final answer:
He Qiaoyuan is writing about the historical importance and economic impact of silver in China, highlighting its role in trade practices, governmental needs, and how its significance spanned across different dynasties.
Step-by-step explanation:
He Qiaoyuan is writing about the global flow of silver to discuss the economic conditions and trade practices that prevailed in China during various historical periods. For example, in the 19th Century, Europe was compelled to use silver for trading with China because China's economy demanded it as payment, likely due to the stability of silver as a currency and the distrust in paper money caused by inflation and heavy taxation during the Yuan dynasty. Additionally, during the Ming dynasty, the need for silver grew as a result of increased governmental expenses such as supporting the imperial family, corruption, and military costs, leading to the confiscation of silver from merchants. This historical context exhibits the significance of the precious metal, both as a medium of trade and a political tool, reflecting the broader economic strategies and the importance of silver throughout China's history.