[VIII]. [1]. Absorptions in general are increased by inanition; hence the use of evacuations in the cure of ulcers. Dr. Jurin absorbed in one night, after a day's abstinence and exercise, eighteen ounces from the atmosphere in his chamber; and every one must have observed, how soon his sheets became dry, after having been moistened by sweat, if he throws off part of the bed-clothes to cool himself; which is owing to the increased cutaneous absorption after the evacuation by previous sweat.
[2]. Now as opium is an universal stimulant, as explained in the article on Incitantia, it must stimulate into increased action both the secretory system, and the absorbent one; but after repeated evacuation by venesection, and cathartics, the absorbent system is already inclined to act more powerfully; as the blood-vessels being less distended, there is less resistance to the progress of the absorbed fluids into them. Hence after evacuations opium promotes absorption, if given in small doses, much more than it promotes secretion; and is thus eminently of service at the end of inflammations, as in pleurisy, or peripneumony, in the dose of four or five drops of the tincture, given before the access of the evening paroxysm; which I have seen succeed even when the risus sardonicus has existed. Some convulsions may originate in the want of the absorption of some acrid secretion, which occasions pain; hence these diseases are so much more certainly relieved by opium after venesection or other evacuations.
[IX]. [1]. Absorption is increased by the calces or solutions of mercury, lead, zinc, copper, iron, externally applied; and by arsenic, and by sulphur, and by the application of bitter vegetables in fine powder. Thus an ointment consisting of mercury and hog's fat rubbed on the skin cures venereal ulcers; and many kinds of herpetic eruptions are removed by an ointment consisting of 60 grains of white precipitate of mercury and an ounce of hog's fat.
[2]. The tumours about the necks of young people are often produced by the absorption of a saline or acrid material, which has been deposited from eruptions behind the ears, owing to deficient absorption in the surface of the ulcer, but which on running down on the skin below becomes absorbed, and swells the lymphatic glands of the neck; as the variolous matter, when inserted into the arm, swells the gland of the axilla. Sometimes the perspirative matter produced behind the ears becomes putrid from the want of daily washing them, and may also cause by its absorption the tumours of the lymphatics of the neck. In the former case the application of a cerate of lapis calaminaris, or of cerussa applied in dry powder, or of rags dipped in a solution of sugar of lead, increases the absorption in the ulcers, and prevents the effusion of the saline part of the secreted material. The latter is to be prevented by cleanliness.
After the eruptions or ulcers are healed a solution of corrosive sublimate of one grain to an ounce of water applied for some weeks behind the ear, and amongst the roots of the hair on one side of the head, where the mouths of the lymphatics of the neck open themselves, frequently removes these tumours.
[3]. Linen rags moistened with a solution of half an ounce of sugar of lead to a pint of water applied on the erysipelas on anasarcous legs, which have a tendency to mortification, is more efficacious than other applications. White vitriol six grains dissolved in one ounce of rose-water removes inflammations of the eyes after evacuation more certainly than solutions of lead. Blue vitriol two or three grains dissolved in an ounce of water cures ulcers in the mouth, and other mucous membranes, and a solution of arsenic externally applied cures the itch, but requires great caution in the use of it. See Class [II. 1. 5. 6].
[4]. Bitter vegetables, as the Peruvian bark, quilted between two shirts, or strewed in their beds, will cure the ague in children sometimes. Iron in solution, and some bitter extract, as in the form of ink, will cure one kind of herpes called the ringworm. And I have seen seven parts of bark in fine powder mixed with one part of ceruss, or white lead, in fine powder, applied dry to scrophulous ulcers, and renewed daily, with great advantage.
[5]. To these should be added electric sparks and shocks, which promote the absorption of the vessels in inflamed eyes of scrophulous children; and disperse, or bring to suppuration, scrophulous tumours about the neck. For this last purpose smart shocks should be passed through the tumours only, by inclosing them between two brass knobs communicating with the external and internal coating of a charged phial. See Art. [II. 2. 2. 2].
[X]. [1]. Bandages increase absorption, if they are made to fit nicely on the part; for which purpose it is necessary to spread some moderately adhesive plaster on the bandage, and to cut it into tails, or into shreds two inches wide; the ends are to be wrapped over each other; and it must be applied when the part is least tumid, as in the morning before the patient rises, if on the lower extremities. The emplastrum de minio made to cover the whole of a swelled leg in this manner, whether the swelling is hard, which is usually termed scorbutic; or more easily compressible, as in anasarca, reduces the limb in two or three days to its natural size; for this purpose I have sometimes used carpenter's glue, mixed with one twentieth part of honey to prevent its becoming too hard, instead of a resinous plaster; but the minium plaster of the shops is in general to be preferred. Nothing so much facilitates the cure of ulcers in the legs, as covering the whole limb from the toes to the knee with such a plaster-bandage; which increases the power of absorption in the surface of the sore.
[2]. The lymph is carried along the absorbent vessels, which are replete with valves, by the intermitted pressure of the arteries in their neighbourhood. Now if the external skin of the limb be lax, it rises, and gives way to the pressure of the arteries at every pulsation; and thence the lymphatic vessels are subject to the pressure of but half the arterial force. But when the external skin is tightened by the surrounding bandage, and thence is not elevated by the arterial diastole, the whole of this power is exerted in compressing the lymphatic vessels, and carrying on the lymph already absorbed; and thence the absorbent power is so amazingly increased by bandage nicely applied. Pains are sometimes left in the fleshy parts of the thighs or arms, after the inflammation is gone, in the acute rheumatism, or after the patient is too weak for further evacuation; in this case after internal absorbent medicines, as the bark, and opiates, have been used in vain, I have successfully applied a plaster-bandage, as above described, so as to compress the pained part.