When T. L. Bradford was compiling his Homoeopathic Bibliography, he obviously wrote to Swan asking about his work, thinking to include it in the "pharmacy" section of the book. The reply from Swan is in Bradford's Scrapbooks at the Hahnemann Collection in Philadelphia, PA.
Nov.20,1889
Dear Doctor:
I have no pharmacy and never had one — I am a practicing physician, who nearly 20 years ago, began making high potencies for my own use — from time to time physicians would try them, and finding high potencies so superior to low began to call for them so much I was compelled to put a price upon them, and as potencies as high and as effective are not elsewhere to be had, the demand continues. This is all there is to it and is not worth noting in your book.
very respectfully
Samuel Swan