Johann Gaspar Spurzheim (1776-1832) was a German physician who was an early proponent of phrenology, the debunked theory that a person's traits can be derived from the shape of the skull.
According to Wikipedia, phrenology is based on the concept that the brain is the organ of the mind, and that certain brain areas have localized, specific functions or modules. Phrenologists believed that the mind has a set of different mental faculties, with each particular faculty represented in a different area of the brain. These areas were said to be proportional to a person's propensities, and the importance of the given mental faculty. It was believed that the cranial bone conformed in order to accommodate the different sizes of these particular areas of the brain in different individuals, so that a person's capacity for a given personality trait could be determined simply by measuring the area of the skull that overlies the corresponding area of the brain.
It may be a wacky concept, but it spawned some great ephemera, including this gem being offered on eBay. It's a rare autograph letter signed "G. Spurzheim" to an unknown correspondent. According the seller's listing, the good doctor penned: "Sir - I send you the third skull for inspection, but request to get it back to-day to have it pack up again with the others. Your humble servt. G. Spurzheim".
The American Book Prices Current, a compendium of auction results, shows only one other Spurzheim letter selling in the last thirty-five years, according to the seller. The letter is laid to a thick board and has some light aging spots, but is in fine condition.
