the epidemic has not yet entered:-a presumption, say the contagionists, that the poison creative of the malady, is imparted from one to another, in the same way as small-pox or measles. And still further, we are told of instances in which the actual importation of the virus has been traced from one region of the globe to another, as was the case, it is urged, with the yellow fever which some years since raged at Gibraltar, and which was, with an evidence too palpable to be disputed, conveyed thither from Malaga.

The reader will by this time perceive the nature and the state of the controversy. The question, it will be seen, is, whether fever engenders fever, as small-pox engenders smallpox; that is, by a specific secreted virus, created or engendered by the morbid actions of another invalid affected by the same malady. In other words, are fevers generally, engendered, sustained, and propagated, by precisely the same laws as those which regulate the propagation of measles, small-pox, scarlet-fever, hooping-cough, and other maladies, that are admitted by all parties to be actually contagious?

Our own sentiments on this contested point, are, if we may so say, intermediate. The facts of the case appear to us to favour the inference, and indeed almost to establish the assumption in an unqualified manner, that the distempers in question are at once contagious, and not contagious; that in some instances they have an independent origin, and in others, are received by individuals nearly, if not precisely, in the same manner as are other morbid secretions."

It has already been stated, and indeed it is a fact generally known, that even those epidemic diseases which are attributed to some unknown states of the atmosphere, as their immediately exciting cause, are, nevertheless, apt to run in families :-that is, if a fever prevail for a given time in a certain district, and one individual of a family fall ill, there is greater reason to fear for the remaining members, than previous to this occurrence: such is likewise most decidedly the case in respect of measles or small-pox. But here, in our minds, consists the cardinal point of distinction between the one and the other infection;-the acknowledged and absolute contagion never affects the frame, how mildly and slightly soever, without producing that state of the secretions by which a precisely similar distemper is capable of being given to another; (similar we mean in kind, whatever be the difference in degree;) while an epidemic fever may have the power of engendering a certain quantum of indisposition in the system of another, without positively reproducing itself, unless the external circumstances and internal condition of the new recipient, act conjunctively in aid of the disease-creating

virus, or unless, as the anticontagionists say, the infectious atmosphere be present. But this is by no means necessary for the continuance and spread of the real contagions, although, even these must be allowed to appear and disappear in a way that is not very susceptible of explication upon any other principle than that of something extraneous or atmospherical being essential to their support and propagation.

We have dwelt rather at large, and perhaps with some appearance of repetition, upon these two points; the one, of similarity, the other, of difference, between the virus of fever and the specific contagions; because, while we do not perceive that it is distinctly pointed out by writers on the subject, it appears to us the only clew for unravelling the seeming inconsistency of the facts connected with the diffusion, on the one hand, and the limits, on the other, of infectious disorders.

Against the opinion of those, (for some there are who argue the absolute necessity of contagion in all instances for the production of genuine fever,) we may relate the following narrative from Dr. Rollo; and we shall afterwards endeavour to shew of what importance such facts are to the moderate and intermediate inference that we have just announced, as, in our minds, the only legitimate one that can be made from a collation and comparison of seemingly opposite facts. One man (Dr. Rollo says) of the Horse Artillery, was admitted into the hospital with suspicious fever; next day, another. This excited enquiry. It was found they came from two different barrack rooms. These were followed by other men, in all amounting to eight; three of whom came from a separate room; the 6 rest from the same room. The rooms were visited by the 'commanding officer. All the rooms whence the infected came, were found to have different bedding from the rest of the 'barracks. The horse artillery being a corps in constant readiness for service, and whose appointments were always complete, had, for convenience of carriage, hammock bedding. The hammocks were rolled up tight every morning the moment the men rose, and they were unloosed when they went into them again at night. At this time we had so much and so constant rain, that this bedding had not been aired or opened, for a single day, for at least two months. The ham'mocks with their bedding, were examined, and the moment they were opened, a very peculiar nauseating smell was 'perceptible. Immediate steps were taken, and no further 'mischief ensued. Thus, an infectious fever evidently arose (Dr. R. says) from the confinement of the eflluvia of a man's own person, in a term of about two months.'

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Here a difficulty presents itself to the contagionist, which we conceive to be insurmountably in opposition to his tenets, inas

much as the maladies in question had, we have every thing but absolute demonstration to prove, an independent origin. Nothing of this kind can ever have become the source of smallpox, or measles, or any other really contagious affection. But, on the other hand, these soldiers, thus infected, would be capable of delivering over, as it were, such infection to another, by direct contact or communication, but the secondary disease would, we conceive, assume a type corresponding to the interior state and external circumstances of the new recipient. And it is not perhaps an unwarrantable postulate, to assume that the disorder thus imparted, would in one part of the world, prove to be typhus, in another, yellow fever, and in a third, plague; and that these respective maladies would, from such source, be made to spread, should every thing around them be favourable to their propagation, while they would immediately decline and die away, should they meet with no pabulum of growth and

nourishment.

In a practical point of view, then, we have arrived, although by a somewhat different route, at pretty nearly the same conclusions with the anticontagionists; and we verily believe that quarantine laws are both unnecessary and inefficient, unless the ship's crew upon which they are enforced, are bound to a place of the same latitude, the same temperature, and the same general circumstances, internal and external, as those from which the vessel had embarked. In other words, we do not believe that the yellow fever could ever by importation be planted in the north of Europe, or that the plague is capable of being brought from the shores of the Levant, into the metropolis of Britain.

It will be seen that we have all along granted to the anticontagionist, the existence and necessity of an atmosphere of fever, in order to insure its continuance. Now, it is a remarkable, and would seem to be a providential circumstance, that although this atmosphere is necessary for the propagation of the particular distemper, those persons who are gradually inured to it, are less likely to be injured, than they who are exposed to it suddenly thus, a child in a family living in the district of an epidemic, would, if affected at all with the complaint, be likely to have it in a much milder form than one who should visit such

family, and in this manner take the disorder. Upon this ground Dr. Adams argues,

That if a ship's crew immediately on its arrival, should be the first to shew the plague or any other fever, the probability is, that the cause is to be looked for in their greater susceptibility, and not in their bringing a contagion with them. If the disease should spread, not only over such a town, but wherever else the diseased may fly, the question may be involved in some obscurity. But should it be

confined to the town, and even if those who escape with the disease, never infect the neighbouring towns or villages, it seems unreasonable to accuse the newly arrived crew of bringing a disease which they cannot convey further.' Epidemics. p. 51.

Admitting, then, the existence, although circumscribed, the origin and operation, of a febri-facient poison, as the result of secretion, it becomes a further inquiry of some interest, in what precise manner this virus finds its way into the system of a healthy individual. Is it through the lungs, or the skin, that contagions and infections are received? Is infection merely inhaled, or is it sometimes absorbed?' From the views which Dr. Adams takes respecting the modus operandi of febrile infection, it may be inferred, (although our Author does not say any thing on the subject,) that he regards the lungs as the sole inlets of infection; and analogy would seem to bear us out in the supposition, that even the more positive contagions are introduced by inhalation; for in those cases where morbid poisons are made to operate upon the body in the way of inoculation, it is always absolutely necessary to open or abrade the outer skin, before the particular effect can be produced. It is not sufficient merely to lay and confine such poisons upon the cuticle. The saliva, for example, of a rabid animal, by means of which hydrophobia is occasioned, might be freely and with perfect impunity made to come in contact merely with the cuticle, provided the part were not in any way wounded; and the inoculation of vaccine matter is always effected by puncturing the skin. It may, perhaps, be objected to this proposed analogy, that the poisous just alluded to, may not be capable of penetrating the outer skin, on account of their comparative density and grossness, while the more subtile and diffusible matter of infection, may possess this power. We find, however, that this is not the case with small pox, the virus of which is possessed of an almost inconceivable and still uncalculated tenuity, but which, nevertheless, when imparted by inoculation, requires, equally with the grosser poisons, that the outer skin should be lacerated or cut, in order to insure its specific effects.* Recent experiments have indeed thrown a

*The matter of small pox must be applied to a wound, in order to induce the complaint. Dr. Rush informs us, he could not induce the small pox by rubbing the matter on the entire skin; and he likewise mentions that a negro girl took some variolous matter mixed with a dose of physic, which produced no sensible effect.' Thomas's Modern Practice of Physic.

This last fact and others would seem to stand in opposition to the opinion that the stomach is sometimes the medium of infection and contagion.

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doubt upon the possibility of any, even the most subtile matter, being communicated to the system from without; and although these experiments are not perhaps absolutely sufficient to disprove the fact of cutaneous absorption, they at least serve to strengthen the presumption, that no infectious or contagious materials are capable of permeating the cuticle.

This is not a question merely of physiological curiosity, but of practical moment. Could it indeed be satisfactorily ascertained, that the breath of an infectious individual is the only thing to be feared, our apprehensions of becoming infected, would of course be considerably diminished: but it would seem that the skin excretes, if it does not take in morbid poisons; and the inhalation of this excretion may equally suffice for the production of its specific effects, as when an individual takes immediately into his own lungs the contaminated expirations of the infected.

We now proceed to a brief inquiry in reference to preventive measures. What are the most eligible means to be adopted in the event of our being visited by epidemics of any kind? Have we grounds for calculating upon the cessation or the extinction of either infectious fevers or contagious poisons?

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The question of prevention or of extinction, leads naturally and necessarily to the question of origin; and this part of the inquiry, so far as it relates to the contagions at least, is involved in great obscurity. Agues are observed to lessen both in number and virulence as lands become drained from staguant water. Plague is a more frequent visiter to a town, in pro-portion as such town is ill-drained or ill-paved; that is, as the excrements of living, and the corrupted parts of dead animals, are suffered to remain on the surface, and to be gradually absorbed by the earth, as was the case with London before the great fire. By an observation of these facts, we are, to say the least, brought very near to actual demonstration, that the poison of marshes in one case, and the putrefaction of filth in the other, are capable, cæteris paribus, of originating the disorders in question: but, when we perceive that no cautions or preventive measures with which we are acquainted, have any influence whatever in arresting the spread and progress of measles, scarlet fever, small-pox, hooping cough; and when, further, we fail of finding any causes, as in the other case, equal to the production of these diseases, excepting their own specific poisons; we are left utterly ignorant as to the essential nature and actual commencement of these poisons. And if we consult the medical records of the ancients, we find the difficulty augmented rather than lessened, for in the older writers on medicine, there is the utmost want of clearness and distinction between infectious and contagious comVOL. VI. N. S. 20