SECT. 8.
As to the fixed Gout, where the morbid Matter remains long in a Place, I take it that many acid Salts and viscid Humours contained in the Blood, occasion a greater Coagulation and Viscidity in the Mucilage about the Joints and the Tendons, than can be easily dispersed and evacuated; and on the contrary growing more viscid and sharp, it distends and vellicates the small Fibres of the Tendons and nervous Membranes, and occasions a Pain proportional to the Degree of Acrimony and Viscidity in the Mucilage about the Joints and Tendons, generally pretty sharp. The Mucilage is affected in the same Manner as it would be from the Affusion of Aqua Fortis, Spirit of Vitriol, or any other corrosive acid or austere Substance, whence it is manifestly thickned and coagulated. This affords a Reason why such a Gout is not only fixed in a particular Limb, but also why it long remains there. The ingenious Dr. Havers explains this Matter very well; he tells us that when the Matter happens to be thick and gelatinous, it is not to be expected that it should be easily and presently discharged out of the Interstices of the Joints, either by being resorbed or evaporated, when the Consistence of it renders it uncapable of insinuating itself into the minute Pores, and penetrating those narrow Avenues through which it is to pass. And according to the Degree and Nature of the Acid in the morbific Humour, it doth more or less coagulate the Mucilage, and the Part affected is sooner or later, with more or less Difficulty, freed from it, either by the Translation of it to another, or by the more happy Exclusion of it out of the Body. The same Author very elegantly explains the Cause of the Knots in the Joints, where he says that it seems to be no difficult Thing to account for that tophaceous Matter, which is sometimes found concreted in those Parts that have been afflicted with this Distemper. It hath been observed, that an Acid and an Austere, being both mixed with the Mucilage, did produce a plain, a notable and white Coagulation, where the Coagulum, though it was made when the Mucilage was cold, was not so soft and tender, nor dissolvable in Water like that which was made with Acids only; but though it would break, remained distinct in it, and being dried, was easily reducible to a fine Powder like Flower, or the fine Powder of Chalk. Whence he humbly conceives, that where-ever the Gout comes to be nodose, there is not only an Acidity in the preternatural Humour, which is separated by the mucilaginous Glands, and mixed with the Mucilage; but it is an Acid austere, which is no sooner thrown into the Interstices of the Joints and the Sinuses of the Tendons which are thereabout, but it produces a Coagulum in the Mucilage, and that such a one as is not easily attenuated and dissolved, so that it lies fixed and imprisoned there, and in Time, as the aqueous and moist Particles are by the Heat and Spirits carried off, the terrestrial and saline Parts concentrated come nearer together, and coming to be immediately contiguous, do mutually adhere, and are concreted so as to produce that Chalk or tophaceous Matter which is in some arthritick Cases to be observed. And as the Coagulum, which may be made by an Acid austere, seems apt to make a Concretion of that nature, so the Colour of the tophaceous Matter doth answer to that of this Coagulation, so as to seem generated in this Manner.