A catholicon is a cure-all; a panacea. This 16-page booklet, published in 1841, promoted a mercury-free cure for scrofula and many other diseases. The following appears in the introduction:
“He,(P. O’Neill) however, avails himself of this occasion, to aver that not one grain or particle of mercury is used in the composition, nor any other mineral, of any description whatever. It is purely and thoroughly the unadulterated extract of the vegetable kingdom.”
Complete text available on Archive.org.
To learn more about the history of medicine and quack cures, see Discovering Quacks, Utopias, and Cemeteries