We shall see, then, that pain is modified differently in each texture, according to the degree of sensibility that it possesses. No one excites the same sensations as the others when it is inflamed. Compare the burning of erisypelas with the throbbing of phlegmon, the pain of rheumatism with that of inflamed lymphatic glands, &c. We shall see also that the sense of heat, developed in each inflamed texture, has a particular character; here it is sharp and biting, there like the feeling produced by fire, &c. There are two general causes that produce a variation in the symptoms of diseases: 1st. the nature of the affected texture; thus, as I have just said, the inflammation of each produces a different kind of suffering. 2d. The nature of the disease; we know that cancer, whatever texture it may affect, has a pain that is peculiar to it; that syphilis and scurvy have also a peculiar character, that is, however, modified in a slight degree in each texture.
The difference of textures not only modifies the symptoms, but affects the duration of them also. Nothing in medicine is more vague, in this point of view, than the terms acute and chronic, in relation to inflammations of the different textures. Most commonly they run their course rapidly in the dermoid, cellular, serous, mucous textures, &c.; on the other hand, they are slow in the bones, the cartilages, and the fibro-cartilages. If we apply this distinction to the same texture, it is very well; thus there are catarrhs, serous and cutaneous inflammations, &c. that are acute and chronic. But if we generalize it, it cannot be understood. A catarrh would be chronic if it lasted two months; but this is the common term of an acute inflammation of the bones; a chronic one continues for a whole year or more. Cutaneous, mucous wounds, &c. last only five or six days if they heal by the first intention; while it requires thirty or forty for a bone, a cartilage, &c. to be cicatrized by the juxta-position of its different parts. A disease cannot be classed, then, by its duration, as an acute or chronic one, except in relation to the same system; when we describe it then in a general way, this distinction becomes void.
Physicians consider abstractedly almost all diseases. When they speak of inflammation they describe the redness, swelling, throbbing and pain, as general attributes, always uniform. If of suppuration, they take for a general standard that of the cellular texture, in phlegmon, without thinking that it is only one of the modifications of suppuration and its product. The same may be said of gangrene, scirrhus, &c. Nothing is more vague and uncertain than the general ideas that are given concerning a disease; they scarcely agree in one or two of the textures.