I acknowledge myself much indebted to you for the Instruction contained in your last Letter. I have met with many Facts which confirm your Opinion of the Origin of Catarhs from Cloaths, Beds, Books &c. Baron Van Swieten in his last Volume of Commentaries on Dr. Boerhave’s Aphorisms in treating upon Epidemic Diseases mentions with Astonishment a Disorder which was peculiar only to the students and Bookseller of the University of Alstorp in Switzerland. May not the Origin of this be traced to the Library of the University from which all the Inhabitants of the town except the Bookseller were probably excluded? A Clergyman from Charlestown in South Carolina who had never heard of your Remark informed me lately that he had almost lost his wife by a severe Catarh which she caught by assisting him in moving his Library from One Room into Another. Instances of Catarh derived and propagated from Beds, Cloathes &c. might be mentioned without Number. But I can by no means think that Catarhs should be confined to these Causes. The Cases you have mentioned I grant a little invalidate the Arguments derived from the Operation of Cold in producing Catarhs, but I beg Leave to add that they do not appear conclusive. Dr. Gaubius in his Pathology speaks of certain remote Causes of Diseases which act only on what he calls the “predispositis.” Thus a few Glasses of Wine will bring on a Fitt of the Gout upon a Man who inherits a gouty Constitution, provided he drinks them at the usual seasons of that Disorder’s attacking him. The same Quantity of Wine will have no Effect upon a Man who is not predisposed, or subject to the Gout. We cannot say however from this that Wine is not One of the remote Causes of that Disorder. Putrid Diseases are brought on by Effluvia from putrefying Animal substances. The City of Edinburgh and many of the principal Cities in Spain are never free from these Effluvia and yet we do Not find they are more subject to putrid Diseases than Other Places. It will not do to say here that the Volatile salt which is constantly extricated from these foecal Matters acts as an antisceptic and prevents putrid Diseases. The same Salt is extricated from Other putrid Matters without producing any such Effect. These Facts however by no means call in Question the Truth of that general Proposition that putrid animal Effluvia generate putrid Diseases. The Operation of Cold and moisture requires a Predisposition in the Body to produce a Disorder in it. A man with weak Lungs seldom fails of having a Cough brought on, or aggravated by wetting his feet, sitting in a damp Room, riding or walking in the night Air. A man who has had the Sensibility of his Lungs encreased by previous warm weather, a warm Room, or by speaking or singing long, or with a loud voice will seldom fail of having a Cough or Defluxion brought on his Breast, if he exposes himself immediately After any of these, to a cold Air. Cold and moisture it may be said influence the Operation of those Matters which bring on Catarhs, and thus appear to act by themselves. But it cannot be so in the present Instances. Moreover in the Histories of all Epidemics, whether Plague, small pox, putrid fevers &c. we find the operation of Cold and moisture in the most sensible Manner upon the Body either in predisposing to, preventing or changing the Type of these Diseases. But I go further; we find several Diseases actually produced by Cold such as the Rheumatism, Angina, and Pleuresy.

After much and painful Enquiry into [remainder missing.]