An inquiry into the propagation of contagious poisons, by the atmosphere

by Somerville Scott Alison

Put a handful of common salt previously made very hot into a saucer, and pour over it an ounce of strong oil of vitriol. The gas is immediately extricated.

It has been already said that the fumigations just noticed are on many occasions highly useful, and their employment is much recommended in all situations where the atmosphere is liable to be contaminated by effluvia from sick persons or from dead bodies; but it is not therefore to be understood that, because the use of these agents has been advocated, it is for the purpose of destroying atmospheric contagion, of decomposing the specific animal poisons which have been supposed to be present, and dissolved in the atmosphere, which is the object, or one of the objects, held in view by the generality of those who advise the use of fumigations. These fumigations have been recommended with the view of correcting what has been treated of as vitiated air, which is distinct from, but which has long been erroneously regarded as, Atmospheric Contagion. On some occasions, great fires of wood, coal, pitch, gunpowder, and the like, have been recommended for the purpose of destroying contagion and purifying the atmosphere. During the prevalence of the plague in London, great fires were kindled in the streets, and, according to some historians, with considerable benefit.

Such great fires produce great agitation of the atmosphere, and it is possible that in this way they may prove useful in improving the condition of that fluid, particularly when, as happened occasionally during the visitations of plague in London, the weather is sultry and close, and when the atmosphere is confined and little agitated, and allowed almost to stagnate.

There is much reason to think that the agitation of the ocean, by its waves and tides, is not more favourable to the preservation of the purity of its waters, than the movement of the atmosphere, by winds and currents, is to the maintenance of its wholesome condition, and when this is lost, to restore it; and in the absence of winds, and when pestilence is raging, the use of combustion on a large scale may with advantage be adopted; but in this climate, where the weather is seldom long calm, the occasions for the employment of that agency can be very rare indeed.

Heat is much used for the purpose of dissipating effluvia, and purifying goods, clothes, letters, &c., which are supposed to be impregnated with contagious matter, or other unwholesome impurities; and there is good evidence to shew that this agent is perhaps the most powerful instrument which is ever employed for the purpose in question.

Heat when applied to an atmosphere containing effluvia will rarefy it, cause it to become lighter, and dissipate it, amid the atmosphere above, where any opportunity is afforded for its egress; and when the heat is employed in the sick chamber, much good is effected by the dissipation of the damp and condensed vapour which cannot fail to be frequently present in that situation.

In the sick chamber, the presence of a fire for even an hour daily is highly useful where there is little opportunity for ventilation, and when the external atmosphere is damp and motionless, for the heat issuing from it, will dislodge and dissipate any effluvia which may have become condensed, and have fastened on the furniture of the apartment.

The condensation of effluvia, &c., is thus depicted in the “Mussulman.” The apartment is that of a prison. —— The pestiferous breath of the surviving was mingled with the effluvia from the dead, and the empoisoned exhalation was condensed on the damp walls, and was seen trickling down in drops of poison to the ground.[^[10]]

[10]. The Mussulman by Madden.

Heat, when applied to clothes which are impregnated with specific contagious matter, or merely impurities or condensed effluvia, is calculated to be highly useful, and where washing cannot be adopted, should never be neglected. Clothes which are thus tainted will be deprived in a great measure of their power of doing mischief, by placing them before a fire for a considerable time, for there is good reason to think that specific contagious poisons will be decomposed, and it is ascertained that condensed effluvia may be dissipated by the application of a smart heat.