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.
Mass. There are two U. S. P. preparations designated by this title, viz., Massa ferri carbonatis, or "Vallet's t Mass," and given in doses of 2 to 5 gr., and klassa hydrargyri, or "Blue Mass," the average dose being 4 gr.