These beautiful watercolour drawings of diseased brain sections come from a book called Reports on Medical Cases, Selected with a View to Illustrate the Symptoms and Cure of Diseases by a Reference to Morbid Anatomy, by Richard Bright.
Bright's book was published in 1827, but these illustrations appeared in a separate volume accompanying the second part of the work, which was published in 1831, and devoted to the pathology of the nervous system.
The complete work included approximately 300 plates. These illustrations are by Frederick Richard Say (1805-1860), a successful portrait painter whose subjects included George IV, Prince Albert, Earl Grey, but the book also included others by C. L. Canton and Bright himself.
From Wellcome Images.
These images are absolutely stunning.
I've found that my own method of studying anatomy has been one of constant reference to pathology; I've never really taken that approach with neauroanatomy, however. I wish I would have known of these then :)