CHAPTER II.

MEDICINE RETARDED—FORMS OF CONTAGION.

The progress of medical science has been much impeded by the operation of the doctrine of atmospheric contagion. From the earliest periods the practitioners of medicine have been in the habit of attributing a very great proportion of the worst forms of disease to that agent; and the consequence has been that little attention has been paid to the investigation of the most difficult, and not the least important department, that of the efficient and ordinary causes of disease.

It was almost a necessary consequence of the possession of such an instrument, ready on all occasions, to solve the problems offered by the occurrences of disease, that no inquiry would be made into those circumstances by which might be detected those influences that conduce to its production. There was ever at hand an agent whose existence all were alike ready to concede, which was amply sufficient to explain the origin and propagation of pestilence.

That being the case, medical men had no inducement to make investigations, and from one generation to another they have gone on in the old way, attributing much to that agency, and leaving uninquired into, with few exceptions, the actual springs of diseased action.

Until very lately little was known of the relation between disease and such important matters as these,—the state of the atmosphere, the severities of the weather, and its other contingent circumstances, the quality of the food and drink, clothing, habits, climate, and the like.

These most important matters received very little consideration, and although much has lately been done to shew their influence in the origin and propagation of disease; yet they are not regarded as so efficient in that respect as they ought to be, and the reason of it is, that the common application of atmospheric contagion to the explanation of the problem, by the vast majority of medical practitioners, puts a stop to the scrutiny which would detect their relation. The fact undoubtedly is, that, in respect to some diseases, little is known, among those intrusted with their treatment, of their causes. This situation of affairs is dangerous, and were physicians to adopt the extravagant measures, which the doctrine of atmospheric contagion suggests, there is a risk that, armed with weapons of so powerful a nature as our medicines are, and moreover, applied to so delicate and nicely strung a machine as the human body, their interference might become downright tampering, and dangerous in the extreme.

But the blame does not lie so much with the present generation of practitioners. It is more the fault of the science than of its present professors.

That doctrine has been taught them, as on established and well authenticated principle. They have too readily confided in the accuracy of their predecessors, and taken for ascertained, that which was only supposititious. Still the public injury is the same, be that as it may; and would the profession perform efficiently its important duties, and deserve that confidence so necessary for the full operation of the art, they would, without delay, inquire into the merits of this case, and turn to the investigation of the causes of disease, the many facts and principles, revealed by the late rapid progress of the sciences.

For the judicious and efficient treatment of disease, a knowledge of its causes is necessary. The disorders being ascertained, the first consideration in reference to the treatment is the cause or causes, and according as the information partakes of certainty or uncertainty, so the propriety of the measures is sure or doubtful.

Without a knowledge of the causes, sure or probable, our efforts are, in some cases, like random blows made in the dark, they may or may not strike the object. It is in general only when the causes are known, more or less, particularly, that medical treatment can be said to rest on a sure and philosophical basis, and to promise the full amount of benefit the art can afford.

For many years the investigation of Atmospheric Contagion has occupied the Author, anxious only to ascertain its actual merits, and to be guided by the result, free of prejudice or bias.

The result has been, that from the actual, constant, and minute observation of disease, from an enlarged inquiry into the circumstances coincident therewith, of the pestilential character of many agencies, and a careful comparison with every agent or form in nature with which we are acquainted, bearing any resemblance to what Atmospheric Contagion must be, if it have an existence at all; that where other hurtful influences are operating, Atmospheric Contagion is needlessly called in to account for their effects, and that it (_i. e._ Atmospheric Contagion) has no existence, properly considered, in the light of an atmosphere holding in solution a specific contagious poison.

Before commencing the argument, it is proposed to notice shortly its history, and the opinions held at this day respecting its nature and qualities.

But as these opinions are very various and conflicting, and as, moreover, from the general confusion of terms, the reader will almost unavoidably become perplexed and unable to understand the merits of the case as treated here or by others, the Author proposes to explain, before going further, what is meant or ought to be meant by contagion, and by contagious air. He is not aware that any plain and uniform method or arrangement of the principles in question is in common use, though some physicians, as will appear in the historical sketch that is to follow, have reduced contagion to two or three distinct kinds, and thus divested the subject of much of its perplexing clashing of terms. They have given fixed meanings to some terms formerly used by all, and even at present by most, with too great latitude.

We will consider, _1st_, Contagion.

That term is, and with propriety may be, used to denote that property, which matter eliminated in a body suffering under disease, has of producing the same disease when applied to another in a state of health, as the matter of small-pox.

Contagion is also used, and will be employed here, to denote the matter itself which we have just defined.

Thus it appears that contagion is used to signify both the property of the matter and the matter itself. This should be understood, as confusion may lead to great misconception. In the same way, the term “heat” is used to denote caloric itself, and also its property.

Contagion, signifying the matter itself, is said to act in different shapes, but here medical men divide. According to those on whose authority most reliance is to be placed, they are the following—three in number:—

_1st_, By the direct application to the body of palpable contagious matter.

_2dly_, By the application to the body of clothes, and the like, impregnated with contagious matter.

_3dly_, By the application to the body of air holding in solution, contagious matter.

To contagion acting in the first-mentioned manner, has almost universally been applied the title, by distinction, Contagion, or immediate contagion; but in order to promote perspicuity, we shall call it Contactual or Palpable Contagion.

To contagion acting in the second-mentioned manner, has been applied the term Fomites (impregnated clothes), but we shall call it Fomitic Contagion.

To contagion acting in the third-mentioned manner, many terms have been applied indiscriminately, Contagion, Infection, Contagious Miasm, Infectious Air, &c. &c.; but to preserve distinctness, and to shew its relation to the other modes, we shall apply to it the title Atmospheric Contagion.

With Atmospheric Contagion, the third mode in which contagion acts, has been confounded by many, air holding in solution, or having commingled with it, gases or impurities, not producing exclusively one disease, as contagious matter does; but productive of deranged health—or at least hurtful to life.

Air thus tainted, has also been called Contagious, Infectious, &c. &c.; but as it is widely different, for the reason mentioned, they should not be confounded; and in order to prevent any accidental confusion, we shall term it vitiated, or, simply, impure air.

There is yet another pestiferous principle called Marsh Miasm, which has sometimes, but less frequently, been confounded with the third mode in which contagion acts, viz. atmospheric contagion. They are very different: the former is confined to marshy lands, and produces exclusively disease of an intermittent character.

Of the first mode in which contagion is said to act, contactual or palpable contagion, there is the most positive proof. That is a settled point capable of demonstration.

Of the second, viz. fomitic contagion, there seems to be no good room to doubt. It is consistent with our knowledge, on points of a like nature, to admit the possibility of its existence; and there is evidence of pretty good character, that contagion does act in that shape, though we are disposed to think that it is not the cause of pestilence so often as is generally understood.

It is to the third mode, viz. atmospheric contagion, that we object. We question its existence for these reasons, _first_, That in the whole course of its history, it fails to supply us with sufficient evidence thereof; _secondly_, That its supposed career is not marked with the same uniformity of effect, and constancy of character, cognisable among other powerful agents, but appears rather to be regulated by no fixed laws; _thirdly_, That the phenomena of disease do not go to shew that it is dependent on atmospheric contagion, the occurrence and dissemination of which, moreover, it could not explain.

We are further disposed to deny its existence at all, for this reason, that its admission is opposed to the testimony of direct observation and of experiments instituted for the purpose.