They are taken, first, from the Natural Humours, Simple, Mixt, and Alter'd: Simple, as the Phlegmon, which is made of Blood, and the Erysipelas of Choler; Mixt, as the Erysipelas Phlegmon, which consists of Blood mingl'd with a Portion of Choler; or the Phlegmonous Erysipelas, which proceeds from Choler intermixt with a Portion of Blood: Alter'd, as the Melia which is compos'd of many Humours, that can not be any longer distinguish'd by reason of their too great Alteration. Secondly, the difference of Tumours is taken from their likeness to some other thing, as the Carbuncle and the Talpa, the former resembling a burning Coal, and the other a Mole, according to the Etymology of their Latin Names. Thirdly, From the Parts where they are situated; as the Ophthalmy in the Eye and the Quinsey in the Throat. Fourthly, from Disease that causeth 'em, as Venereal and Pestilential Buboes. Fifthly, from certain Qualities found in some, and not in others; as the Encysted Tumours, which have their Matter clos'd within their proper Cystes or Membranes, and so of many others.
How many kinds of Tumours are there that comprehend at once all the particular Species?
They are four in Number, viz. the Natural Tumours, the Encysted, the Critical, and the Malignant.
What are natural Tumours?
They are those that are made of the four Humours contain'd in the Mass of the Blood, or else of many at once intermixt together.
What are the four Humours contain'd in the Mass of the Blood?
They are Blood, Choler, Phlegm, and Melancholy, every one whereof produceth its particular Tumour: Thus the Blood produces the Phlegmon, Choler the Erysipelas, Phlegm the Oedema, and Melancholy the Scirrhus. The Mixture of these is in like manner the Cause of the Erysipelatous Phlegmon, the Oedomatous Phlegmon or Phlegmonous Erysipelas, and the Phlegmonous Oedema, according to the quality of the Humours which are predominant, from whence the several Tumours take their Names.
What are the Encysted Tumours?
They are those the Matter whereof is contain'd in certain Cystes, or Membranous Bags; as the Meliceris, and the Struma or Kings-Evil.