The Benares is still their favorite…the Amoy men run on the Patna when 5-10 difference, the Chimmo men run on the Benares.
John Rees in Chimmo Bay to William Jardine in Canton, October 19, 1834.*
Benares (Varanasi) was one of the two opium growing regions in Bengal, supplying the auctions in Calcutta (the other was Patna). The value of each year's crop of opium varied year to year, place to place, depending on slight differences in taste, weight, etc. As the quote above illustrates, Chinese buyers in Shenhu Bay (Chimmo) were in 1834 more inclined to purchase Benares, while their competitors in Xiamen (Amoy) were that year buying up a great deal of Patna (when the markup from Lintin prices was under ten taels). These market differences could be very significant to Jardine-Matheson's profit margins, and opium captains like John Rees were constantly working to take advantage of this for their firm.
*Source: JM:B2 7 [R. 495, No. 23] Rees, Quanzhou, 10.19.1834