3. in connection with local bleeding, reference may be made to other modes of accomplishing the same object temporarily, by accumulating the blood in one part of the body, beyond its normal proportion, and thus diminishing the amount circulating for the time. This may sometimes be of considerable importance, when the general condition of the system forbids the loss of blood, and yet the indications may be strong at a particular time to diminish the amount circulating, as in certain hemorrhages for example. There are various methods of accomplishing this object, to which reference has been already made, or will be made hereafter; but there are two which especially belong to this place; the tourniquet, namely, and the exhaustion of air over a certain part of the body.

Tourniquet. Several different influences upon the circulation may be exerted by this instrument, according to the method of its application. if drawn tightly so as to arrest all circulation in a limb, it effects one purpose; if applied so as to compress the main artery of a limb, and yet permit the venous circulation, it effects another. But, as an agent of temporary depletion, it is applied with moderate tightness, so as to compress the veins and interrupt the movement of the blood through them, without arresting its course through the main artery of the limb. It thus causes an accumulation of the blood in the limb, which necessarily produces a deficiency elsewhere; and in this way the effects of general depletion are obtained for a time; and if the measure be applied at the same time to several of the extremities, it will be perceived at once that the effect must be very great. Of course care is required not to continue the application of the tourniquet too long, lest serious injury be done to the limb by the excessive congestion to which it is exposed.

Exhaustion of the Air. By applying such an apparatus to one of the limbs that, by means of the air pump, the atmospheric air may be exhausted from around it, and the ordinary atmospheric pressure thus removed, it necessarily happens that the blood of the general circulation is pressed into the limb, so as to fill the vacuum as far as possible, and consequently very much to diminish the amount circulating elsewhere. All the effects of a general loss of blood may thus be temporarily produced on the brain, heart, and lungs, without the inconvenience arising from its permanent loss. The plan is simply an extension of dry cupping; except that, in the latter case, the blood is often slow in being restored to the circulation, being sometimes perhaps coagulated, and almost always to a certain extent extravasated.* c. Indications and Contraindications of Bleeding.

The indications which bleeding is calculated to fulfil, are 1. to lessen the quantity of the blood when in excess, 2. to lower its quality when abnormally rich or stimulant, 3. to relieve vascular irritation and inflammation through the two agencies just mentioned, 4. to obviate local determinations of blood dependent on excessive action of the heart, 5. to relax spasm and relieve nervous irritation in general by directly depressing the nervous centres, 6. to awaken the susceptibility in any organ rendered d. Therapeutic Application.

* In the London Lancet (Oct. 1864, p. 462) is a paper by Dr. Theodore Junod, of Paris, giving an account of some experiments made on a healthy young man, intended to test the efficiency of this method of derivation or temporary depletion. Very soon after the application of the apparatus to one of the lower limbs, the part became red, swollen, and somewhat heated; at the end of 40 minutes the pulse was a little increased in frequency and diminished in volume, the face began to become pale, and slight coolness was felt in the hands, ears, eyelids, etc. In 80 minutes, the voice became feeble, and the pulse thready and 90 in the minute; the inspirations were slower and deeper; the general temperature was somewhat reduced; and a disposition to yawn was observed. In 15 minutes longer, the pulse fell suddenly to 40, general relaxation took place, perspiration broke out on the face, the pupils were dilated and vision lost, there was tinnitus aurium; in other words, syncope was approaching, and might soon have been complete. Thus the effects of general bleeding were obtained, even to faintness, without the loss of a drop of blood. No evil followed the experiment, though the limb remained somewhat swollen for a time. {Note to the third edition.) insensible by active congestion of the nervous centres, and 7. to promote absorption by depleting from the blood-vessels. it is contraindicated in general debility; a scanty, anemic, or depraved condition of the blood; nervous irritations of all kinds dependent on direct depression or debility of the nervous centres; and pure or predominant dilatation of the heart.

There is no remedy more important than this; perhaps none which so frequently saves life. That it is susceptible of abuse, and often has been greatly abused, there can be no doubt; but this is only an argument in favour of a careful study of its powers for good and evil, and of great watchfulness in its use; none for its abandonment altogether; and the practitioners who reject it, and oppose their own prejudices or fears against the experience of all ages, not only deprive themselves of a most important agent for good, but assume a responsibility which might well make a conscientious individual shudder. Though never one of those who might be considered as special advocates of the lancet, I fear that, in the reaction from a too indiscriminate, and sometimes reckless use of it, the profession is now in danger of erring in an opposite direction, and cannot but think that the general tendency is rather to an injurious neglect, than to an injudicious use of the remedy. in my experience as a hospital physician, I have seen many patients past all hopes of cure, whom early and judicious bleeding would probably have saved; but very seldom one, in whom I had reason to think that an abuse of the remedy had been productive of serious injury. it will be impossible in this place to specify every case in which bleeding may be advantageously resorted to. My object, in the following remarks, will be to suggest principles, and give illustrative examples, which may enable the student to decide for himself, as to the propriety of using the remedy in any particular case that may come under his notice.