De lingua qua maximum est morborum acutorum signum

Prothus (Protho) Casulanus Senensis




Prothus (Protho) Casulanus Senensis


We know very little about Prothus (Protho) Casulanus Senensis except that he was from Siena, hence his Latin name Senensis. His book was novel and daring for the time. He stipulated that one can make medical diagnosis from the appearance of the tongue and that the tongue is a rich source of symptoms for acute illnesses. The first edition was published in Florence in 1621 in Latin. The book was republished in 1626 in Cologne by Matthaeum Smitz, also in Latin. A third Latin edition was published in 1651 in Ulm, Germany.

The 148 page book that we have in our collection is the 1626, second edition. De lingua qua maximum est morborum acutorum signum, Opus, in re Medica, nou(v)i argumenti, which more liberally translated is: The tongue, a major (source) of sign for acute illness - A medical study, a novel argument.

The book is divided into five volumes and each in further chapters. There are specific sections dedicated to yellow tongue (Lingua flava), Black tongue (Lingua nigra), Pale tongue (Lingua pallida), Purple tongue (Lingua livida), Red tongue (Lingua rubra) or discolored (Lingua decolori). Casulanus dedicates a section on what we would call today Dysgeusia or unpleasant taste. Specifically, in Volume III chapter VIII (page 103) he discusses the occurrence of bitter, sweet, sour and salty taste in the mouth associated with various conditions and what they may represent. For instance, to the appearance of bitter taste in the mouth is correctly identifies a potential cause as the presence of yellow bile in the stomach that made its way to the mouth during reflux/vomit (Indicat etiam linguae amaritudo bilem flavam redundantem in ventricolo quo vomitu … Facile antem a ventricolo in os bilis flava ascendit). The yellow bile was considered one of the four humors that, if out of balance would cause disease. Hence Casulanus’ knowledge and focus on the yellow bile. Otherwise, there was very little known about the physiology of the stomach. That will have to wait until 1776 when Lazzaro Spallanzani (1729-1799) starts to study the role of the gastric juice.

Digital Versions

De lingua qua maximum est morborum acutorum signum 1626 (second edition) >>>