This section is from the book "A Practitioner's Handbook Of Materia Medica And Therapeutics", by Thos. S. Blair. Also available from Amazon: A Practitioner's handbook of Materia Medica and Therapeutics.
Calendula, Marigold. This remedy has been used internally, and its tincture is official in 20% strength. What rational basis there may be for its internal administration has never been made very clear to me. Externally, it really does what arnica is reputed to do, and is in every way superior to the latter agent. It is applicable to open wounds and to burns, and serves to prevent contracting eschars owing to its tendency to produce exudation. The non-alcoholic calendula is a valuable antiseptic in surgery and gynecology.