Funny you should mention this, Debs. There is currently a discussion taking place on Henriette's herblist about Ellingwood's Eclectic Practice of Medicine which is now available on Google books, downloadable and printable as a pdf.
http://books.google.com/books?id=2NNLAAAAMAAJ&printsec=frontcover&dq=finley+ellingwood+The+Eclectic+Practice+of+Medicine
Paul Bergner has also recommended R. Swinbourne Clymer, author of the Physiomedicalist classic Nature's Healing Agents (Still in print, since 1908.) Paul says that he wrote what may be the best exposition of the Thomsonian system ever printed, in 1905. Very practical. Apparently Clymer was trained in England, and got his Md from the last Physiomedical College, in Chicago, and was a student of Lyle there.
Paul said "This is basic Thomson, with the century of experience by the physiomedicalist physicians on both side of the Atlantic added." I guess this would cover general Victorian knowledge of herbal medicine. The book can be downloaded from
http://www.archive.org/details/thomsoniansystem00clymiala
Matthew Wood's book, "The Practice of traditional Western Herbalism" is supposed to give a really good description of the major themes in herbal medicine. I have it, but haven't read it yet.
Other books I have but haven't read yet are Steven Pollington's Leechcraft about Anglo Saxon healing methods and Mary Beith's "Healing Threads: traditional Medicines of the Highlands and Islands". Joan Lane has edited "John Hall and his patients". This book is only available from the Shakespeare Birthplace Trust but can be ordered online. John Hall was Shakespeare's son-in-law and was reputed to be the best physician in the country, which may have been the reason why Shakespeare returned to Stratford in his later years to have his kidney condition dealt with. John Hall kept two manuscripts, one for all his successful treatments and another for those where the patient did not recover. When he died, his widow sold all his books to the another eminent medical man, who had the success book printed but lost the other one, which would have had details of the herbal remedies given to Shakespeare in it!
I must do some research about the priory in Northumberland which the Time team excavated a couple of years ago. There was a medieval script attached to it which gave all the remedies the monks used and they went to the valley where the majority of the herbs grew that they gathered.
Have you checked Henriette and Michael Moore's site for all their ancient online herbal texts?
Sarah
[edited to make the links clickable]