Journalistic and historical perspectives on 19th century insane asylums

This article from The Atlantic today looks at medical monograph on “Types of Insanity.” In addition to the kinds of proofs of insanity that Dr. Wycherley and others give in Hard Cash, we have this gem:

In some cases we have but little difficulty in making a diagnosis by the letter alone, because of the striking incoherency, which the individual may restrain in conversation but which he indulges in when left to himself; and in suspected cases, where patients are on their guard, it is well to ask them to write a letter.

One of the peculiarities of the letters of the insane consists in the use of illustrative diagrams, keys of explanation, and strangely coined words.

“Letter writing”?  “Keys of explanation”?  “Strangely coined words”? Good thing that sounds nothing like our seminar.