At all stages of the disease the gall-bladder is usually found full of bile, which is apt to be dark during the collapse and more watery after reaction has commenced.
The spleen is small, pale, and, as a rule, firm, but occasionally it is soft.
The kidneys present no marked changes when death has taken place early in the attack, or at most only exhibit a lighter color than usual of the cortical substance and a darker one of the pyramids. They show that the arteries are comparatively empty and that the veins are congested. Similarly contrasted appearances are met after death from obstructive disease of the heart and other causes that produce obstruction of the venæ cavæ. In the tubules, later on, fatty degeneration of the epithelium has been observed, and some cylindrical casts. These alterations, especially of the tubules, are most marked when death occurs in the stage of reaction, and are then apt to be accompanied by more or less hemorrhagic transudation. The urinary bladder is always contracted after death in collapse; after febrile reaction its mucous membrane may be more or less coated with false membrane.
The brain and the spinal marrow offer nothing peculiar; their venous systems are everywhere more or less engorged, and sometimes effused blood has been found in the spinal canal.
In the state of the respiratory organs the most important facts are that in algid cholera the lungs are always more or less collapsed, "shrunk and small, and lying back in the chest, toward the spine," and that, so far from being congested, they are (with the exception of a small portion of their posterior part rendered dense by hypostasis) singularly bloodless, dry, and tough. As might be inferred from these conditions, they are also lighter in weight than natural. To Dr. Parkes belongs the credit of having first described this very important fact in the morbid anatomy of cholera, as follows: "In fourteen cases the lungs were completely collapsed, appearing in some cases like the lungs of a foetus. In three cases they were considerably, in eight slightly, collapsed, and in the remaining fourteen cases the collapse was in some altogether, and in some partially, prevented by old adhesions."46 So Dr. Sutton found that the average weight of the two lungs during collapse was about twenty ounces, and after reaction—that is, after the passage of the blood into the pulmonary artery had become completely re-established—about forty-five ounces. In the latter condition also the lungs presented the usual signs of congestion of those organs, being dark-red throughout or in portions only. Sometimes also they contained masses or nodules of apparent hepatization, and of these some may have undergone partial softening.
46 Med. Times, 1848, p. 378.
In absolute conformity with the condition of the lungs that has been described is that of the heart. If the lungs are bloodless, it follows necessarily that the left side of the heart must be empty, and almost as necessarily that the right side of the heart must be distended with blood. All careful investigators of the subject agree that such is the condition of the heart when death takes place in cholera during the stage of asphyxia. All report that the pulmonary artery is either empty or that it contains a small quantity of dark and usually of thick blood; that the right side of the heart and the coronary veins are distended with blood of the same description, while numerous ecchymoses exist along the course of the coronary veins; that the venæ cavæ are filled with half-coagulated blood of a tarry aspect; and that even the femoral and splenic veins contain similar blood. On the other hand, the left ventricle of the heart is usually contracted, and contains a very little semi-fluid blood, with perhaps a small and pale clot. This engorged condition of the right cavities and emptiness of the left cavities of the heart diminish very slowly during the passage from collapse to reaction, during which time the pulmonary blood-vessels are being gradually replenished. Besides the thick and tarry aspect of the blood above described, it has been observed that when the blood is withdrawn by means of a pipette, its globules rapidly subside and are surmounted by a transparent serum, and that such blood may remain for a long time uncoagulated. The red corpuscles are said to be pale and viscous, but not adhesive, and the white corpuscles abnormally numerous and easily crushed. In the free intervals are observed "very pale little objects, slightly elongated and constricted in their middle," which multiplied in blood kept for one or two days at a temperature of 38° C. (100.4° F.).47 If death does not take place until reaction is far advanced or has merged into a febrile condition, the left ventricle is usually found not contracted, and it contains a quantity of blood. The term "usually" is employed to show that even to this rule there are some exceptions, and that, as in all other diseases, the issue does not depend absolutely and exclusively upon a definite degree of any anatomical lesion, but upon the aggregate condition of all the functions upon which life depends. The pericardium, like the pleura and the peritoneum, may be covered with a saponaceous film which is albuminous.
47 Rapport sur le Cholera d'Égypte en 1883, par M. le Dr. Strauss, etc.
In looking now over the field that has been traversed in the foregoing pages, and searching for some link that will unite in a consistent whole the causes, symptoms, and lesions of cholera, it is evident that only one factor can possibly be so described. That factor is the gastro-intestinal flux. This it is that produces the vomiting and the purging; that prostrates the patient and wastes away in a few hours the fullest and the firmest form; that chills the limbs and afterward the trunk; that thickens the blood so that the capillary vessels can no longer convey it, and that spreads a cyanotic shadow over the whole surface of the body; that cuts off the supply of blood from the lungs and heart; that paralyzes the nervous system, ganglionic as well as cerebro-spinal; that obstructs the kidneys and arrests their secretion; and that, acting through the several links of this pathological chain, becomes the cause of death. But the question still recurs, What is the cause of the gastro-intestinal flux? To this also, in the light of observation, it is possible to give only one answer. It is a specific poison which originates in Hindostan, and, being taken into the stomach and bowels, not only produces in the individual the symptoms and lesions of cholera, but is capable of multiplying itself and rendering infectious the discharges from the stomach and bowels of the subjects of the disease, so that it may be transmitted from one person to another round the whole circumference of the globe. Regarding the form and nature of that poison little or nothing is definitely established, beyond what has already been stated as the result of Koch's observations. As far as they go, they harmonize with a long-prevalent opinion that the cholera poison consists of certain microscopic germs, which, on being received into the bowels, propagate their kind and destroy the epithelium. It is believed by some that these bodies are products of the rice-plant on the banks of the Ganges, and that, having once originated the disease, the germs contained in the discharges become mixed with water or are borne upon the wind, and enter the system of new victims, who, in their turn, disseminate the plague. This theory will be further considered below.
Another view, that of B. W. Richardson, is that, "as pus undergoes changes which convert it into a septic poison, so the excreted matter from the alimentary canal is equally capable, under peculiar conditions of oxidation, of producing an alkaloidal organic poison, which, soluble in water, but admitting of deposit on desiccation," becomes the agent for disseminating the disease. In these theories a false datum and a hypothesis are offered us in place of the fact which we seek. The cryptogamous nature of the essential cause of the disease has no positive proof, but only the probability of coincidence in its favor. There is no proof, because one after another organic form has been alleged to be the essential generator of the disease, and each has been proved to be either not peculiar to cholera or has been shown to be present in other diseases than cholera.