METASTASIS.
As this term is frequently used by practitioners, it may be well to explain that it is a Greek word signifying a removal from one place to another, employed as a technical designation in describing a change of the seat of disease from one part of the animal structure to another, which is by no means uncommon: for instance, when the feet are attacked with fever, that malady will appear to remove itself to some other and probably distant part, and fix itself on the lungs or other viscera, the same way that inflammation of the lungs and other parts of the upper structure will change amongst themselves, or from their own seat of disease to the feet.[34] I have even known superpurgation (occasioned, in a pair of horses, by undue, but not severe work when under the irritation of the medicine) to cause fever of the feet, by a metastasis, changing the seat of irritation from the internals to the extremities—a very palpable case in point.