Thus many nosographers saw bilious pleuropneumonia as a complicated disease: if one saw the homology of relations existing between 'gastricity' (i volving digestive symptoms and pains in the pit of the stomach) and irritation of the pulmonary organs, which suggests inflammation and respiratory disorders, different symptomatological sectors, apparently deriving from distinct morbid essences, make it possible nonetheless to give the disease its identity: that of a complex figure in the coherence of a unity, and not that of a mixed reality made up of mixed essences.