But the case of the nurse in the “Dreadnought,” suggests questions respecting the fate of nurses attending choleral patients in other places. If it be true, as it is believed to be, that they are affected by cholera in a degree scarcely, if at all, exceeding that of persons in the same social condition otherwise employed, the fact would appear to furnish a strong general argument against the contagious nature of the disease. How does it happen that persons living in the same room with, and constantly handling and helping patients in all stages of the disease, so constantly escape its power, if it be not only readily communicable by the person to healthy persons, who are in juxtaposition with its subjects for a short time, but capable of being propagated by their clothes, in distant places, after undefined periods?
Five fresh nurses were brought into Haslar Hospital to attend the choleral patients. They passed at least half their time, night and day, in the ward, and slept there in their turn. They were much employed in rubbing the patients, and consequently leaning over them, administering injections, removing ejections, &c., in short performing all the duties of their place, which were at once trying, laborious, and likely to excite apprehension,—yet none of them was affected.
These, and such facts, of which a multitude might be accumulated, may be objected to, on the ground that they afford negative evidence only, and that one positive proof of contagion would outweigh them all. Be it so. But where is the positive proof to be obtained, and by what distinguishing mark is it to be recognised? Suppose one of the five new nurses brought into Haslar to attend on the subjects of cholera had been attacked by the disease, during, or soon after that service, must it be admitted that the disease was communicated by the patient to his nurse? It is submitted that it should not. Before such admission can be held necessary, it must be shown that the disease which attacked the nurse was not derived from places outside the Hospital, which he was allowed to visit, or from the cause diffused in the air of the neighbourhood, in less or greater concentration, and manifesting its powers relatively to the degree of concentration, and the force of pre-disposing co-operating agents.
It would be unsafe to assert that cholera can never, under any circumstances become contagious; but if the conditions which lead to its acquiring that property, the crisis by which it is effected, and the period of its accomplishment cannot be ascertained, the policy of searching for it may be questioned. Truth is desirable on its own account certainly, but the truth or falsehood of a position is relatively important according to its bearing on the business of life; and if the position that cholera may become contagious could be demonstrated, to what practical purpose could it be turned? It does not appear how it could be used to stay the progress or mitigate the power of the disease. It would not likely be proposed as a reason for separating the sick from the healthy, or enforcing quarantine regulations of any kind. He must be a very ardent believer in the self-propagating power of cholera who would urge authority to shut up, and surround with guards, houses standing in many different parts of Gosport, Portsea, Portsmouth, and Southsea, and half the towns and villages of England. There is little danger of such measures being adopted now, although they were seriously put forth by the General Board of Health, under sanction of an order in Council, in October, 1831; but, if they were put in force, it would not be rash to assert that they would aggravate the evil immensely. They would turn fear into terror, and interfere with, or prevent the ordinary offices of humanity; thus, at the same time, supplying one of the most powerful predisposing causes of the disease, and fearfully augmenting the misery and danger of the affected. In such a state of things it would be impossible to persuade persons of character, like those who, without hesitation, undertook the duty of nursing the choleral patients in Haslar, to enter on similar service for eighteen-pence a day; nay, it might be impossible to persuade men to enter on such a forlorn hope by any consideration.
Although the pro-contagionist might not be moved by facts and inferences like these, he would perhaps be disposed to ask the man propounding them, some such question as the following.—As you do not admit that contagion is the cause of cholera, what in your opinion is the cause? In return it would not be impertinent to say to the querist, what is the cause of ague? Something emanating from the surface of the earth, on the spot, or not far from the place where its subjects are resident?—something so subtle as to be imperceptible by the senses, and hitherto beyond the scrutiny of chemists and meteorologists. He would, it is presumed, answer in some such terms, or if he attempted any much more precise and instructive, he would proceed without the warrant of fact and experience. Such at least would be the general reply of the profession, and a more complete and unconditional confession of ignorance of every thing respecting the essence of a most powerful and wide spread cause of disease cannot be made. Though we know a good deal of the places most prolific in its production, as well as of the agents which co-operatively increase its force, we know it solely by its effects.
In very similar, if not precisely the same terms, it seems to the writer, should the question, what is the cause of cholera, be answered. Little, if anything more can be affirmed respecting its origin, but almost every thing authentic in its history, progress, and phenomena, testify to its having a local source, and generally very limited scope of operation. Thus it appears simultaneously in different, distant places, leaving intermediate places untouched. It attacks in one town a particular district, street, or portion of street, beyond which it does not travel. In another town it shows itself among distant portions of the inhabitants, leaving long spaces unscathed. Again, while one town suffers severely from it, another in the neighbourhood has not a single case then, or thereafter; or the town which escapes this season, falls fatally under its sway the next, when all the rest of the country is clear. These and such circumstances as these, point as clearly as it is possible to point at the endemic source of cholera, although the essential cause of the disease cannot be ascertained.
But although we cannot in cholera, more than in periodic fever, ascertain the essential cause, there is no difficulty in showing the accidental auxiliary agents, which both in disposing to, and co-operating with it, give it much of its prevalence, and most of its fatal power. They consist in whatever deranges healthy action, and impairs constitutional vigour—such as unwholesome insufficient or irregular supplies of food—over labour—crowded and defective ventilation—dissolute habits, including vicious indulgences in intoxicating drink, and want of personal and domestic cleanliness—apprehension, anxiety, and inordinate emotions of the mind; and defective drainage, including sewerage, with resulting accumulation of organic matters. For the last, at least, the State and the authorities acting under it ought to be held responsible.
Whether the last named agent—defective drainage and its consequences—constitutes any thing positive to the essential cause of the disease, or is necessarily connected with it, or whether it only co-operates with those specified before it, in lowering the standard of health, by the production in excess of hydrogen and other gases, injurious to life, and thereby predisposes the body, through augmented susceptibility, for the action of the essential cause cannot be determined. It is pretty certain, however, that neither it in any quantity, nor any amount of the other agents classed with it, as disposing and co-operating powers, in the production and extension of cholera, can of themselves create it. If they could, not only part of Ireland, but of places nearer home, must have been decimated, some of them depopulated.
Whether excess or deficiency in the electric element, or disturbance in its ordinary relations, in the place where cholera appears, acts any part in the production of the disease, is not known. It seems probable that there is something abnormal in its distribution and movements; but that is all that can ever be reasonably conjectured, at least for the present, respecting it.
Whether there is any affinity between the essential cause of cholera and periodic fever, and, if any, of what kind, are questions that naturally suggest themselves in investigating the etiology of the former. That the question, as far as it relates to a certain affinity in the two cases, should be answered affirmatively, the following considerations seem to shew.