Years in print:
The St. Louis Magnet, a monthly publication designed to illustrate the philosophy of human nature, was issued in 1848 by Dr. T.J. McNair. It was much too literary and philosophical to be ranked as a medical journal. In 1849 Drs. J.C. Heberling and F.G. Sitton purchased interests in the periodical, which was discontinued late in the same year.
(From the Encyclopedia of the History of Missouri by Alexander N. De Menil, 1901).
Another report says it began in 1846.