清代內務府是皇帝私有財政的管理機構，從康熙朝起內務府儲存的銀兩逐漸增加，至乾隆朝已達千萬兩銀。乾隆初年，皇帝曾下令運用部分的銀兩經營當鋪，前後共設了二十六座當鋪，並且規定年息為百分之十二。不過當時北京民營的當鋪也相當多，所以內務府開的當鋪利息收入往往不及百分之十二。乾隆皇帝因此下令關閉大部分的當鋪，其資金改借給商人，稱為發商生息。 內務府借給商人的資金，其利息大致維持在百分之十二的水準，比民間的借貸三分利息低得多，但是這些商人借款的年限長達一、二十年，以致單利計算，百分之八點三的年利息數目約略等於本銀，負擔相當沉重。況且，商人借款有一部分是投資鹽業產銷；另一部分則是應付朝廷各種名目的捐輸款項。本文所敘述三個鹽商家族王至德、范清濟、王廷獻，他們都是皇帝的御用商人，皇帝給予他們運銷鹽業的特權。在十八世紀時，鹽業的產銷面臨許多困難，而皇帝的需索卻又不斷增加。商人因借債過多而破產，乾隆皇帝便派人去抄家。由此可知，皇帝為了維護自己私有的財富，不借犧牲了商人的利益。

　　　　　In the Ch'ing Dynasty, the Imperial Household Department constituted the emperor's "personal bureaucracy." From the K'ang-hsi reign, the monetary revenue of the Imperial Household Department had gradually increased, reaching 10 million tales in the Ch'ien-lung reign. In the early years of the Ch'ien-lung era, the Emperor had ordered a portion of the silver to be used for opening up pawnshops. There were 26 pawnshops in total, and the fixed rate of interest was set at 12% per year. However, there also existed many private pawnshops at Beijing competing with the royal ones, hence the overall rate of interests even for the royal pawnshops would often lie well below 12%. Owing to that, the Emperor ordered most of the royal pawnshops to be closed down, and the money to be lent to the merchants instead. This became known as "accumulation of interests through lending capital to the merchants." (發商生息）The interest rate of the capital lent by the Imperial Household Department to the merchants was set at an average of 12% per year, which was comparatively lower than that of the private sector. The period of loan was set to run from 10 to 24 years, therfore the total amount of interest was more or less equal to the original borrowed amount of capital, turning the loan into quite a heavy active debt. Moreover, part of the loan was being invested in salt production and sales, another was to be paid as donations to the government on various accounts. The three salt merchants and their lineages described in this article, Wang Chih-te（王至德）, Fan Ch'ing-chi（范清濟）, and Wang T'ing-hsien （王廷獻）, were all under the Emperor's patronage, enjoying the privilege to monopolize the salt business. During the 18th century, both the production and trade of salt were confronted with many difficulties, while the Emperor kept asking for more money from these undertakings. The merchants went bandrupt as a result of the heavy loans and donations, and the Emperor disperor dispatched officials to confiscate their properties. Hence it can be concluded that the Emperor tried to maintain his own wealth at the cost of the merchants'.