Although it covers a generally later period than noted, an article by Sharon 
Lowe, entitled "The 'Secret Friend': Opium in Comstock Society, 1860-1887" 
in "Comstock Women, The Making of a Mining Community" edited by Ron James 
and Elizabeth Raymond, provides good information about the use of opium in 
Virginia City, Nevada.

Another book, "Hidden Heritage: Historical Archaeology of the Overseas 
Chinese," edited by Priscilla Wegars of the Asian American Comparative 
Collection, has an article about opium paraphernalia by Jerry Wylie and Richard 
E. Fike, and another about the ceramic and opium inventory of a Chinese store 
in California by Ruth Ann Sando and David L. Felton.

Hope these give you some additional material for your research.