Ewell, then practicing in Savannah, Georgia, wrote this self-help book for southern residents, directing his book toward plantation owners. It was "the constant friend of a large number of slave-masters. In emergencies it was not uncommon for planters to sit with book in hand by the bedside of a sick Negro, look up the symptoms, compare the remedies and then administer the drug. Not infrequently their wives would minister to sick slaves" (Morais, The history of the Negro in medicine [1968]  16-17.),. The book underwent at least 11 editions, under different titles. Digital facsimile of the Baltimore, 1811 edition from the Internet Archive at this link.