This idea is not hypothetical; the injections of which I have spoken are the most evident proof of it. Let it not be said that it is a transudation after death, analogous to that of the bile through the gall-bladder: if it were so, not only the fine fluids injected would go out by the excretories and the exhalants, and return by the veins; but in oozing through the pores, they would fill the whole cellular texture. On the contrary, nothing escapes into the cellular texture, around the vessels by which the injection passes; there is then a continuity of tubes from the artery which has received the fluid, to the excretory, the exhalant, or the vein which transmits it. These are the communications of the capillary system that explain how the skin becomes livid on the place on which a dead body has for a long time lain, as on the back, for example; how by turning a dead body, so that the head may hang down, it becomes full of fluid; how, on the contrary, by placing upright the body of one dead from apoplexy, asphyxia, &c. the capillary system of the face is freed in a great measure from the blood it contained; how an erysipelas disappears on a dead body, when the blood, arrested during life on a part of the skin, by the vital action, is spread after death to all the surrounding parts; how every kind of analogous redness of the skin, and even of the serous surfaces, disappears because the blood goes by the communications of the capillary system to the neighbouring organs. During life the tonic action retains the fluid in a determinate part; abandoned to its gravity, and other physical causes, after death, it soon disappears from the part in which it was accumulated, on account of the innumerable communications of the general capillary system. I would observe to those who examine dead bodies, that these considerations are very important. Thus we must not judge of the quantity of blood which penetrated the inflamed peritoneum or pleura, by what is seen twenty-four hours after death; local irritation was a permanent cause that fixed the blood in the part; this cause having ceased, it escapes from it. A serous membrane may have been very much inflamed during life, and yet exhibit almost its natural appearance after death; as it is in erysipelas. I should have been often tempted from opening dead bodies, to deny the existence of an affection which had been real. The same remark applies to the inflamed cellular texture, the mucous surfaces, &c. Examine a subject that has died of angina, which during life gave the deepest red colour to the pillars of the velum pendulum pelati, to the velum itself and the whole pharynx; after death, the parts assume nearly their natural colour.