Plumbe was one of the most outspoken critics of Willan and Bateman’s morphological system of skin disease classification. In his Practical Treatise he was the first dermatologist to attempt to produce a classification of skin diseases based on etiology. [Plumbe] "attempted to organize his material according to the ‘constitutional causes’ of each disease, along with ‘due consideration of the organic structure and physiology of the part of the skin on which it is seated’ . . . Along with the conflicts between the champions of the morphologic and etiologic approaches to the study of skin diseases, another development of the future was anticipated in the work of Samuel Plumbe—the introduction of anatomic evidence on the macroscopic level in the support of theories of pathogenesis . . . In the next decade [Plumbe’s] anatomic methods and habits of thought were picked up by Erasmus Wilson, improved and incorporated into the British dermatologic ethos well enough to allow the transition to the cellular theories of disease to be made more smoothly in Britain than it was in France, where efforts of the same nature on the part of Pierre Rayer were ignored” (Crissy and Parrish, pp. 34-36). Plumbe was the first to perform manual epilation (hair removal) as part of the treatment for diseases of the scalp. The frontispiece of the Practical Treatise illustrates Plumbe’s division of skin diseases into five major categories; the engraved image is printed in reddish ink with other colors added by hand. Crissy and Parrish, The Dermatology and Syphilology of the Nineteenth Century, pp. 34-37.