Were the hatters of New Jersey "mad"?

Conventional wisdom holds that the "Mad Hatter" of Alice's Adventures in Wonderland earned his name because he exhibited psychotic behavior from mercury poisoning. The first description of mercurialism in hatters was published by J. Addision Freeman, M.D., in Transactions of the Medical Society of New Jersey in 1860, just 5 years before Lewis Carrol's famous tale. But it is unlikely that Alice's creator was aware of this obscure provincial report. Numerous subsequent studies of hatters in New Jersey showed that the hatters' shakes were rampant among the immigrant workers. The pathologic shyness of mercurialism, however, was not noted in New Jersey hatters until 1912. The idea that hatters were "mad" stemmed from popular perceptions more than from medical knowledge. Nor did medical studies lead to elimination of mercury in felt hat manufacturing. The hatters' occupational disease was curbed only in 1941 when mercury was required for the manufacture of detonators in World War II. The hatters of New Jersey were not only not mad, but neither were they, the physicians, nor the public of the period sufficiently angry to control the conditions under which the hatters worked.