[14] Hunter on Inflammation, p. 350.
[15] By peculiar action, I do not here mean what is commonly understood by the term specific, but the action which is proper to the artery, considered as an individual, in opposition to the action of the heart and arteries, considered in general as an entire circulating system; for one part of this system may act less powerfully than another, and may be more dilated, &c.
[16] The distance to which this will extend, depends chiefly upon the quantity of blood which is lost, and the size of the vessel which is affected.
[17] This depends upon the operation of the sympathy of association. Sympathy was, in the preliminary dissertation, divided into that of association, and that of equilibrium; and it was mentioned, that the same parts might be made to exhibit either of these, but that naturally the sympathy of association is chiefly, and most easily exhibited by those parts which are similar in structure, and contiguous to each other; and, in them, the action spreads fastest. At the same time, if the action continues long, or be very strong, it may be propagated to dissimilar parts, and produce either a very extensive, or an universal action, which is just a greater degree of the sympathy of association. In this case, it has, however, been called universal sympathy.
[18] The solution must, upon the principles already laid down, be both weak, and only so cold as to reduce the sensation of the part to its natural condition, that is to say, so as to abate the morbid feeling of heat; because, if we make it otherwise, we may injure the powers of recovery, and perhaps induce gangrene. The application ought not to be so cold as to excite the sensation of coldness, at least in any considerable degree.
[19] Bark is useful and necessary in every case of erysipelas, after the inflammatio valida has abated. Local applications, of a stimulating nature, are also useful at this period, as will afterwards be mentioned, when the inflammatio debilis comes to be considered.
[20] From what has been said in the preliminary dissertation, we may understand how moisture should tend to induce a secretion. Agents frequently excite conditions somewhat similar to their general properties: Thus, putrid matter tends to induce the action of descent, and consequent putrefaction. We likewise experimentally find, that, if moisture be applied during a general increased action, it induces perspiration, unless it be conjoined with cold, which lessens the action.
[21] The proper way to use electricity, in this case, is to draw scintillæ from the part, the patient being insulated.
[22] Fomentations are made, by applying a soft cloth, dipped in any warm fluid, (commonly water) to the part. Sometimes the cloth is wrung hard, in which case it is chiefly steam which is applied.
[23] Poultices may also be made, by boiling pounded linseed-cake, or from potatoes, or mashed vegetable leaves (which are the cheapest for hospitals), such as tussilago, &c.