CHAPTER II.. Section I.--Pathology.

SECTION I.--PATHOLOGY.

The doctrine now universally accepted and prevailing regarding its Pathology is, that a poison, virulent, subtle, and unknown, has been absorbed, and primarily infects the blood, so that, after a longer or a shorter time, a primary disease of this vital fluid is produced, and that the poison undergoes an enormous process of multiplication in the living body of the cholera patient, as the direct result of this morbific process so established, and that changes are induced in the function of respiration directly consequent on this alteration of the blood.

This altered condition and rapid change in the life-sustaining principle of the blood, the loss of nerve-power, the impaired circulation and tendency to congestion, are the proper and distinguishing features of the disease; and the term "Algide," first used by the French Pathologists, very happily describes one of the most remarkable and constant symptoms, namely, the diminution of animal heat. The loss of temperature and its consequent effects upon the circulation, depressing and prostrating the nervous power, impairing and paralyzing the respiratory organs, suspending the functions of the liver and kidneys, enfeebling the action of the heart, and causing the capillary vessels of the mucous tissues to expand and pour off the serous fluid from the blood and every muscle and tissue of the system, with great rapidity, essentially constitute the phenomena of the Cholera. The constantly increasing augmentation of the poison and its intensified effects measure the malignity, the violence, and the rapidity of the disease.

It is this multiplication, and the disturbance which attaches to it, that in each case constitutes the disease and destroys life. Of this fact the circumstantial evidence is abundant and conclusive, and may account in part for the violence of the disease in its first irruption in any particular locality. The vomiting, purging, and cramps are now generally considered as secondary and non-essential phenomena, for numerous cases of cholera have occurred in every section where it has prevailed in its more violent and malignant form without exhibiting these symptoms. The poison was so potent, and its progress so rapid, that life was extinguished in a very short time. In its first irruption at Muscat, cases are reported in which only ten minutes elapsed from the first apparent seizure before life was extinct. Dr. Milroy, speaking of the violence and rapidity of the disease as it occurred in 1817, and again in 1845 and '6, at Kurrachee, observes, that "within little more than five minutes hale and hearty men were seized, cramped, collapsed, and dead." Instances of death taking place in two or three hours are extremely common. When it broke out at Teheran, in May, 1846, Dr. Milroy observes, that "those who were attacked dropped suddenly down in a state of lethargy, and at the end of two or three hours expired, without any convulsions or vomitings, but from a complete stagnation of the blood." In many places during its prevalence in 1832, and subsequently in 1834, and in 1848 and '9, the rapid fatal character of the earlier cases was observed and reported as the most severe and hopeless. In various cities and villages in our own country, cases of this description were not unfrequent. In all these the destructive nature and rapid process of the disease was so depressing and overwhelming as to prevent any effort of the "vis naturæ" to resist its progress.

Hence, from the autopsy of those who have fallen victims to its baneful influence in the first stage, or within forty-eight hours of the attack, no alteration of structure in any organ or tissue has been discovered. But in those cases where death has occurred at a later period, some lesions and slight changes in the appearance of some tissues have been traced. The more important of these, illustrative of the characteristic effects of the disease, are, in brief, the following:

The follicular structure of the intestinal canal has been found slightly swollen, and the intestine partially filled with a turbid, inodorous, semi-diaphanous fluid, resembling thin starch, or rice-water, and is supposed to be the remains of that peculiar secretion which had taken place during life. This fluid is sometimes acid, and sometimes alkaline. In the small intestines it is found in an unmixed condition. It consists of two liquids of different consistency; the one thick, the other thin. The latter constitutes the rice-water stools, and may be passed off without admixture with the thicker substance. The colon has been found generally much contracted, and the mucous membrane and the sub-mucous cellular tissue of the digestive canal presenting evident marks of congestion, in some cases approaching to a sub-inflammatory state, generally in spots or patches of various sizes, the color of these varying from a very dark congestion to a more roseate hue. The glands of Brunner and Peyer, as well as the solitary glands, are greatly enlarged. The stomach and bowels are frequently of a paler color than natural, both in their inner and outer surfaces. The liver, the spleen, and the kidneys have been found engorged with blood. The urinary bladder is always contracted, and empty. The gall-ducts are sometimes contracted, at other times not. The vena porta and all the other abdominal veins are loaded with black blood, resembling tar in its color and consistency. The membranes of the brain and cord are generally found congested, and the substance of the brain more or less dotted with small points or specks of blood than usual.

"The most common appearances in the lungs," says an eminent pathologist, "are the presence of blood in the large vessels, chiefly or solely; the collapse and the deficient crepitation arising from the more or less complete absence of air and blood, and from the approximation of the molecular parts of the pulmonary substance. In other cases there is more blood in the minute structure, a corresponding dark color of the lung, and a variable amount of frothy serum. The right side of the heart and the pulmonary arteries were generally filled, and in some cases distended with blood; the left side and aorta were generally empty, or contained only a very small quantity of dark blood; the left side evidently had received little or no blood, but had continued to contract, in some cases even violently, on the last drop of blood which had entered it."

Such are some of the prominent appearances which the body has presented when the patient has died in the first, or pulseless stage of the disease. But in other cases, where the premonitory stage has been definitely marked, and attended with diarrhoea or other depressing disorder affecting the alimentary canal, and where the patient has continued under the influence of the disease for a longer period, and has passed through the usual successive stages of it, other additional appearances have been noticed, which are here omitted, as they are of a secondary importance, and belong especially to the more protracted cases.

The post-mortem appearances, the phenomena of the disease, the Algide, or diminished animal heat, and the loss of nervous power, all tend to show an obstructed circulation and consequent embarrassment of respiration resulting in the non-aeration and non-oxydation of the blood, from which a long train of secondary and non-essential symptoms arise. For it is affirmed that the mechanical part of respiration remains in a good degree perfect, and that the heart evidently continues to beat in many cases till stopped by the want of blood in the left side and by its accumulation in the right side. Hence, for the cause of this arrest of the circulation of the blood through the lungs, we are forced to look to the condition of the blood itself, and the deranged action of the ganglionic nerves.

Attempts have been made to trace out from analysis the exact chemical changes in the order of their occurrence which attend the period of transudation from the blood into the intestinal canal. "The most prominent phenomena of cholera," says Dr. Aiken, "during this period of transudation, consists in separation of the water and of the salts of the intercellular fluid (of the blood) through the mucous membrane of the intestinal canal, and the retention in the blood of an important excess of albumen and of blood-cells, with apparently less, but in reality with great diminution of the salts and fibrin."

"The inorganic constituents," continues the same author, "if compared to the water, are during the first four hours increased, because at this time the water is passing off with great rapidity; afterwards, as the salts pass off, the disproportion is lessened, and after eighteen hours or so, the proportion of salts is greatly diminished, and, if compared with the organic constituents, the diminution is enormous. With respect to the individual salts, there is in the blood a relative preponderance of phosphates over chlorides, and of potash salts over soda salts. By the end of eighteen hours or so, the blood-corpuscles are left in a most abnormal condition; the great loss of water and of salts, especially of the chloride of potassium--a most important constituent of the blood-cells--at once leads to the conclusion that their functions must have been greatly impaired. Accordingly, Dr. Schmidt found that the amount of oxygen contained in them was lessened by one-half." Dr. Robertson affirms that the "fibrin of the blood is usually in large amount and coagulable with great firmness;" while Dr. Parkes, speaking of the same condition of the blood, and relying on the accuracy of his analysis, observes, "The presence of fibrin in the blood was not indicated by any coagulation either in or out of the body; and whether coagulated or not, the blood has usually a dark color; but it generally acquired an arterial tint when brought into contact with the air in thin layers." * * * "When we remember the great share taken by the blood-globules in the respiratory and heat-furnishing processes, it is scarcely possible to avoid concluding that their loss of salts is connected with the characteristic cyanosis and lowered temperature in cholera." "The diarrhoea coincides with the first chemical changes in the blood--the transudation of some of the constituents of the serum." Hence the phenomena of the disease may thus be traced from this process as the starting-point. All other chemical changes in the blood, and the most marked symptoms, such as the abnormal respiratory process, follow as a matter of course. Such is the theory of the nature of cholera, now advanced and sustained by the most eminent pathologists, which embraces the doctrine previously advanced that the blood is the primary seat of the disease, and becomes contaminated by the absorption of a specific poison.