This section of the book is from "The Complete Herbalist" by Dr. O. Phelps Brown. Also available from Amazon: The Complete Herbalist: The People Their Own Physicians By The Use Of Nature's Remedies.
MEDICINAL PART. The root.
Description. -- Comfrey has an oblong, fleshy, perennial root, black on the outside and whitish within, containing a glutinous or clammy, tasteless juice, with divers very large, hairy, green leaves lying on the ground, so hairy, or so prickly, that if they touch any tender parts of the hands, face, or body, it will cause it to itch. The stalks are hollowed and cornered, very hairy, having leaves that grow below, but less and less up to the top; at the joints of the stalk it is divided into many branches, at the ends of which stand many flowers, in order one above another, which are somewhat long and hollow like the finger of a glove, of a pale, whitish color; after them come small black seeds. There is another sort which bears flowers of a pale purple color, having similar medicinal properties.
History. -- Comfrey is a native of Europe, but naturalized in the United States, growing on low grounds and moist places, and flowering all summer. The root is officinal and contains a large amount of mucilage, which is readily extracted by water.
Properties and Uses. -- The plant is demulcent and slightly astringent. All mucilaginous agents exert an influence on mucous tissues, hence the cure of many pulmonary and other affections in which these tissues have been chiefly implicated, by their internal use. Physicians must not expect a serous disease to yield to remedies which act on mucous membranes only; to determine the true value of a medicinal agent, they must first ascertain the true character of the affection, as well as of the tissues involved. Again, mucilaginous agents are always beneficial in scrofulous and anaemic habits. Comfrey root is very useful in diarrhoea, dysentery, coughs, hemoptysis or bleeding of the lungs, and other pulmonary affections; also in leucorrhoea and female debility; all these being principally affections of mucous membranes.
It may be boiled in water, wine, or made into a syrup, and taken in doses of from a wineglassful to a teacupful of the preparation, two or three times a day.
Externally the fresh root, bruised, forms an excellent application to bruises, ruptures, fresh wounds, sore breasts, ulcers, white swellings, etc.