The arguments used by this author against terrestrial contagion are,
1. “It has often happened that hundreds of men in a camp have been seized with the dysentery, almost at the same time, after one shower of rain, &c. People under similar circumstances must be subject to similar diseases: and yet it often happens that dysentery begins with a few people, and spreads itself by degrees until a multitude are affected.”
This argument rather militates against himself; for, if dysentery or any other disease was occasioned by an evident general cause operating upon persons in similar circumstances, all of them ought to be taken ill at once; but Dr. Mosely owns that they frequently are not. There must, of consequence, be something less evident which determines the disease to particular persons, while the general cause operates equally upon all. This less evident cause we call contagion.
2. “It is incredible that the smelling a little human blood, that had stood some months in a phial, gave the man a dysentery mentioned by Pringle; or that the person Forestus speaks of got the plague by only putting his hand into an old trunk; or that the shaking an old feather-bed, which had lain by seven years, raised a plague at Wratislau, which destroyed five thousand persons in twelve weeks, as related by Alexander Benedictus, &c.—Such things may be true, but, when probability is shaken, reason always inclines to skepticism.”
Here our author most evidently contradicts himself; for in the beginning of the paragraph he tells us that the things related are incredible, and in the end of it, that they may be true. The argument, if it may be so called, is mere assertion. It is incredible that the smell of putrid human blood in a vial should produce the dysentery. Why should this be more incredible than that smelling to a charged vial should ensure an electric shock to the person who did so? This is entirely a question respecting a matter of fact, not of speculation. The same is the case with the rest. It is not more incredible that, if the infection of the plague was in a trunk, a man should get the plague by putting his hand in it, than that he should be burnt if he put his hand into a trunk full of hot ashes. Before the Doctor decided in such a positive manner, he ought to have proved that no infection could be contained in a trunk; but this, though the very point in question, he takes for granted, first telling us that the contrary is incredible, and then that it may be true!
3. “We observe in camps and hospitals, that those people whose dirty employments subject them in a particular manner to a depravation of their habits, seldom escape the present epidemic; and this gives rise to the vulgar expression, and very incorrect notion, of catching the disease. And we observe that others from the slightest deviation from regularity lose the power by which the body resists diseases, and they are also attacked. But these attacks are not to be attributed to infection: for those people who keep the vital and animal powers in uniform confederacy, by temperance and calmness of mind (for fear, by lowering the vital energy, subjects the body to disease) nourishing diet, proper clothing and cleanliness, and keeping a free and regular passage for all excretions, are proof against the assaults of foul and pestilential air. Such people seldom suffer even by the plague itself: while all around them perish.”
The first sentence of the above paragraph is so obscurely worded, that it is difficult to know the author’s meaning. I know not of any lawful employment so dirty that it necessarily subjects the person who practises it to a depravation of habit. The next ascribes every thing to intemperance and fear; from which, it seems, we are to infer that none but drunkards, cowards, and dirty, naked ragamuffins, are ever seized with epidemic diseases. But of this we are able to bring a direct disproof. I suppose Dr. Mosely will not say that the celebrated Prince Eugene of Savoy was either a coward or a drunkard; that he had a dirty employment, wanted proper food or clothes, or was deficient in personal cleanliness; yet, when in the marshy parts of Hungary, he was in danger of death from an epidemic dysentery, notwithstanding that he was so careful in respect of diet, that he had pure water brought him every day, probably from a considerable distance. How came he to be affected by the distemper under such circumstances, while Count Boneval, though as an inferior officer he probably enjoyed fewer advantages, remained free from it, taking only a small quantity of Peruvian bark daily? It is uncertain whether the bark did really preserve him or not; but the case of Prince Eugene plainly shows that sobriety, temperance, valour and cleanliness are not sufficient to ward off an epidemic disease, if people come in the way of infection.
4. “It should follow, if contagion were supported by infected bodies, that no person should ever escape infection (as at Oxford assizes in 1577[87]) who was within the sphere of its action; and that those who were entirely secluded from it, and free from all contiguity to infected people, or substances, as the collegers were in the town of Cambridge, when the plague was last in England, should be exempt from it.
“But, in opposition to this, Rhazes lived 120 years, an often practised in plagues. Hodges remained in town, and attended the sick, during the great plague in 1665. Kaye was in the midst of practice in the sweating sickness in 1551, without any inconveniency. Procopius informs us, that during a terrible plague at Constantinople, in 543, which almost destroyed the whole city, no physician nor other person got the plague by attending, dressing or touching the sick. Yet most of the Capuchins, the Jesuits, the Recollets, the Observantines, the Barefooted Carmelites, the Reformed Augustines, all the Grand Carmelites, the Grand Trinitarians, the Reformed Trinitarians, the Monks of Loretto, of Mercy, the Dominicans, and Grand Augustines, who kept themselves secluded in their several convents, and took every precaution to avoid the plague, while it raged at Marseilles, perished by it.
“There are no epidemical nor contagious diseases that attack every person who breathes the same air, or that is in contact with the infection, else whole regions would be depopulated. The habit must be graduated, or adapted, for the reception of a disease. In some constitutions of body the access is easy, in some difficult, in others impossible. But where the revelation of this mystery is to be found, none can tell.”