CHAPTER XI.

THE AVOIDANCE OF DISEASES MARKED WITH PALPABLE CONTAGIOUS POISONS—THE LIMITED RANGE OF ACTION OF CONTAGION.

It was shewn in the first part of this work, that the contagious poisons of disease, such as the matter of small-pox, are known to act in two modes only, _first_, by application of the palpable matter itself to a person, or by contactual contagion; _secondly_, by application of clothes or other such substances, impregnated with that matter, forming what has been styled fomitic or mediate contagion. It was also shewn, that their action through the medium of the atmosphere, has never been ascertained. Experiments were detailed, which were performed on those poisons, to ascertain their capability to become dissolved in the air, and their evidence was as strong as it possibly could be, against their possessing that attribute.

It was, in short, fully ascertained, that contagious diseases do not propagate by atmospheric contagion.

Contagious diseases propagate among those who expose their persons to contact with the matters or clothes impregnated with them. There are many facts of an incontrovertible character, which prove the occasional operation of the former mode at least, and to render probable, that of the latter; and hence, whatever attention is paid to cleanliness of the sick person, his apartment, and to the prevention and removal of vitiated air, persons touching a body, when there is present on its surface specific contagious poison, such as the matter of small-pox, or even handling clothes, which have become impregnated with it, incur a risk of being affected with the same disease, by means of that matter or fomitic contagion.

In all the contagious diseases (those in which there is eliminated a palpable poison, or matter capable of causing the same disease in others), their respective matters are invariably formed, and are apt to propagate in the modes specified, so that visitors and other attendants should ever be upon their guard, the first not to touch the sick person at all, and the latter not to touch more than is necessary, and to take precaution to render the risk as slight as possible.

Subjoined is a list of diseases which are known to be contagious, or to be possessed of a matter of the nature referred to, and that are therefore wont to be propagated by contact with the sick, or with his clothes.

Small-Pox. Scarlet Fever. Measles. Chicken-Pox. Cow-Pox. Itch. Plague. Porrigo. &c.

These are almost the only diseases known in this country, which are positively ascertained to be characterized by the elimination of contagious matter, and which, therefore, there is any risk of getting by contagion. The continued fever of this country has been supposed, by some physicians, to be a contagious disease, from there being sometimes observed pimples on persons affected with it; but that is by no means an ascertained point.

Those above enumerated seem to include all the most important diseases in this country, which are capable of being propagated by contagion, acting in either of the two ways already described. Some of them are capable of affecting the same individual only once, and some affect persons as often as they are exposed to their specific contagious matters.

How comparatively small, then, is the range of contagion,—an agent which has been thought to accomplish worlds of mischief, and to destroy almost whole communities.

Visitors may approach within a very short distance of persons afflicted with these distempers, without danger of suffering, provided they do not touch the bodies or the clothes.

They have nothing to apprehend from the atmosphere, if attention is paid to the maintenance of its purity,—such as is necessary in other situations, as well as in the sick-room.

Never brought into that immediate contact with the poisons which is necessary for their propagation, they stand in need of no directions for their removal or counteraction.

Those persons, on the other hand, who are called upon to touch the patient and his clothes, are exposed to danger; and they should lessen its amount, by instantly putting their hands into warm water, and by freely washing them, with the assistance of soap,—and that ablution should be performed after each instance of contact.

I have often had occasion to feel the pulse of persons ill of the worst forms of confluent and black small-pox, and any risk that has thereby been incurred, has been removed or remedied by immediately washing the hand as directed.

In addition to washing, after that process is done, a small quantity of a strong smelling liquid, such as Lavender water or Eau de Cologne, should be poured into the hands. Their grateful odour may hide or cover that of the apartment, which the attendant may mistake for contagious air, as is often done, and thereby remove groundless apprehension. These seem to be the chief precautions that are necessary for meeting the dangers of contagion, if there is included what is sometimes used, viz. a covering for the hand,—a glove and the like,—which, as being harmless, and such as may possibly be useful, should be employed; and likewise the avoiding of eating and drinking with the same instruments and vessels used by the sick persons.

The propagation of disease by contagion, in the modes already stated, though it can take place, and though it sometimes does take place, still there are the strongest grounds for supposing it a comparatively rare occurrence.

I have already shewn, at the beginning of this work, that in one form, the atmospheric, contagion never operates, and I am now prepared to assert, that in the two forms in which alone it can act, that the instances of its undoubted agency are by no means nearly so common as they are commonly believed to be, especially in connexion with those acute diseases, accompanied with fever.

It is my belief, founded on much observation, study, and reflection, that almost all cases of those contagious diseases, arise from causes or circumstances connected with those great agencies already detailed at full length, as inductive of pestilence in general, and of a nature epidemic, endemial, meteorological, and the like.

I am led to the opinion, that this course of origin, even in contagious diseases, is the rule, and that the origin of disease, by contagion, whether contactual or mediate, is the exception. The grounds of this opinion are,—

_1st_, A fact well ascertained, and of which I had lately two instances, in houses contiguous. Infants neither inoculated, nor vaccinated, lie with their mothers and others ill of small-pox, and do not take that distemper.

_2d_, Women, while labouring under small-pox, occasionally bear children in perfect health.

The above are common occurrences, and I am in possession of the particulars of several which came under my own observation in the beginning of 1838.

These cases prove the occasional, nay, the frequent inactivity of contagious poison, even when applied in a palpable form, and in a recent condition, to the bodies even of those who are not protected against its operation by inoculation for cow or small-pox, or by a previous attack of disease; and this inactivity is observed too, when the most ample opportunity is afforded for the action of the poison, viz. while children are asleep together in the same bed, and when infants are upon the breast of mothers affected with small-pox.

Those very children who thus escape taking disease by contagion, are frequently known to be seized with that identical disease, at some future time, varying from months to years, when no other case is known to exist in the neighbourhood, and where there is no room to suspect the operation of contagion.

It is, I believe, as common as the contrary course, for small-pox, and other reputed contagious diseases, after appearing in one house in a town or hamlet, to break out in others at a distance and in different directions, and not to progress from that which was first attacked to those lying adjacent, or to spread around as from a centre.

For example, the first case of Typhus Fever which occurred in my practice, in January 1839, was at Meadow Mill, a village half a mile north of Tranent; the second case was at a hamlet called Redcoll, about four miles east; the fourth and fifth cases occurred in Tranent; while the sixth and last for that month appeared at Elphinstone, a village situated about two miles to the south-west of Tranent.

I am led also to the opinion, that the ordinary cases, even of those diseases which are known to be occasionally propagated by contagious poison, do not arise from contagion, but from other circumstances and agencies; by the history of the plague, for while that scourge is ravaging in the East, and destroying hundreds daily, it frequently ceases, immediately upon the overflowing of the Nile, which buries and covers the pestiferous soil, and the putrefying materials which had been exhaling noxious emanations.

This sudden departure or cessation of plague, upon the overflowing of the Nile, proves that contagion, though it may be the cause of some cases of that disease, is not the occasion of the vast majority,—the great mass of cases, in short, which constitute the Epidemic; and goes far to prove that distemper to be dependent upon an unwholesome condition of the soil, or vitiated atmosphere, and other widely extended and unwholesome agencies, of a nature totally different from specific contagious poison.

That fact goes to prove, in reference to one disease, viz. Plague, what I believe holds with all other contagious distempers, that contagion, at most, is only an occasional, while such influences as those to which reference has been made, are the constant and general causes of sickness.