Topical bleeding will also, in part, operate, by simply abating the action, in consequence of the mere loss of blood; for, as the blood is withdrawn immediately, by different orifices, from the vessels of one part, that part, and those near it, may be supposed to suffer sooner, and to a greater degree, than the rest of the system. The branches which yield the blood, will even suffer considerably, for a time, although the loss of blood be very trifling, and produce no effect on the system. Thus, if one small artery be divided, we find, that, although the quantity of blood which flows from it be very inconsiderable, yet it is sufficient to produce evident changes in that vessel, making it contract, and become smaller, although the vessels in other parts be not at all affected. This depends upon the peculiar[15] action of the individual artery being affected[16], and the contracting state of the orifice, spreading along the branch and trunk by degrees[17], by which less blood is made to circulate through it. Bleeding from a vein, however, has not the same effect; because the quantity of blood in a part, is not so immediately dependent upon the state of the veins; and because veins are not the seat of much action. When we divide a small vein, we find, that it, by degrees, contracts, and transmits less blood, or closes completely; but the blood from the part does not circulate faster, nor is less blood sent to that part than formerly; therefore, topical bleeding from veins near the affected part, can have no great superiority over general bleeding. [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.