This is a term employed by Prof. Graves to denote blisters which are allowed to remain on for two or three hours, and are then removed. The primary action of a blister is that of a local and general stimulant; its secondary, that of an evacuant and depressant. It is the first of these which it is desired to obtain from these "flying blisters." Dr. Graves speaks highly of their value in fevers, and in all cases in which the vital powers are greatly depressed; and adds, that the application of flying blisters over the region of the heart, the epigastrium, the inside of the legs and thighs, has been attended, in his practice, with the most striking benefit. They should on no account be left on long enough to produce vesication.

2956. Therapeutic Uses

In ordinary cases of Inflammatory, Continued, or Remittent Fever, blisters are rarely called for; but when the disease is complicated with inflammation of the lungs, heart, brain, or other important viscera, blisters prove of the highest service. In the advanced stages, also, when the vital powers are greatly depressed, the action of the heart feeble, and where there is much debility, flying blisters {ante) are stated by Prof. Graves* to restore, in a remarkable manner, the vital powers. In Bilious, Remittent, or Yellow Fever, a blister to the whole length of the spine, in a certain number of cases, allayed the irritability of the stomach in every case except one. It was also found useful when cerebral complications existed. In Typhus and Typhoid Fevers, the great objection to the use of blisters is the danger of the blistered surface degenerating into troublesome or gangrenous sores. As a general rule, sinapisms and turpentine stupes are preferable. In the Coma of these Fevers, a blister to the scalp may, however, have the effect of arousing the patient.

* Diseases of Females, p. 202. Lib. of Med., vol. v. p. 94.

Clin. Lect., vol. i. p. 149.

2957. Diseases of the Brain, Spine, &c. In Sanguineous Apoplexy, very little benefit will accrue from blisters; but in Serous Apoplexy, which may be distinguished from the former by its comparative mildness, great advantage will often be obtained from the application of blisters to the calves of the legs, and sometimes to the nape of the neck. When a tendency to apoplexy exists, an open blister at the nape of the neck is often attended with the best effects; a seton or issue, however, is preferable.

2958. In Insanity, Blisters Are Sometimes Beneficial

The nape of the neck is the situation usually chosen; if, however, there is no unusual heat of the scalp, it is better to apply them over the vertex, or to cover at first the anterior, and afterwards the posterior part of the head, by a blister, which is to be speedily removed after the skin has become inflamed. This remedy is chiefly indicated in cases attended with stupor. (Dr. Prichard.) Under some circumstances, blisters to the extremities appear serviceable. (See also Delirium.)

2959. In Delirium, Blisters Have Been Advised To The Head; But Dr

Copland justly observes that they have been used much too indiscriminately, and that he has seen them most injurious in this situation. Thus applied, they are only beneficial when the powers of life are sinking fast, and the delirium is attended by stupor, a cool head, and sunk and collapsed features, as in cases of low or adynamic fevers. When this affection is consequent upon febrile determination of blood to the head, blisters to the inside of the legs, &c, may be useful derivatives; but they often occasion so much pain and irritation in this situation as to thereby counteract, particularly in the turbulent state of delirium, any good they might otherwise produce. (Copland. §)

2960. In Hydrocephalus, the value of blisters has been the subject of much difference of opinion. In the acute stage, they appear to be prejudicial; but in the second stage, when the active inflammatory symptoms have subsided, much benefit will be derived from a blister at the nape of the neck, kept open for several weeks. Blisters to the extremities have been found serviceable by some practitioners. From the intimate relation which exists between the brain and the stomach, Golis, an eminent German authority, was induced to place a blister over the latter region, and he states with the best effects. (Dr. Cheyne.*)

* Op cit., vol. i. p. 159. Cyc. Pract. Med., vol. ii.

Lib. of Med., vol ii. p. 134.

§ Dict. Pract. Med., vol. i. p. 496.

2961. In Acute Inflammation of the Brain, a blister should not be placed on the crown of the head, except when coma supervenes, as otherwise it appears often to aggravate the intensity of the symptoms. Applied, however, in succession, to the nape of the neck, it is a remedy of great value. Dr. Hope considers that, in the advanced stages, blisters may be applied to the shaven scalp, not only with safety, but often with surprising advantage. Good effects sometimes result from their application to the extremities.

2962. In Paralysis, Epilepsy, Chorea, and in some other Spinal and Nervous Affections, blisters to the spine prove useful. They should be kept open for some time; but are, on the whole, inferior in efficacy to setons or issues.