II. Absorption from the mucous membrane is increased by applying to its surface the austere acids, as of vitriol, lemon-juice, crab-juice, sloes.

When these are taken into the mouth, they immediately thicken, and at the same time lessen the quant.i.ty of the saliva; which last circ.u.mstance cannot be owing to their coagulating the saliva, but to their increasing the absorption of the thinner parts of it. So alum applied to the tip of the tongue does not stop in its action there, but independent of its diffusion it induces cohesion and corrugation over the whole mouth. (Cullen's Mat.

Med. Art. Astringentia.) Which is owing to the a.s.sociation of the motions of the parts or branches of the absorbent system with each other.

Absorption from the mucous membrane is increased by opium taken internally in small doses more than by any other medicine, as is seen in its thickening the expectoration in coughs, and the discharge from the nostrils in catarrh, and perhaps the discharge from the urethra in gonorrhoea. The bark seems next in power for all these purposes.

Externally slight solutions of blue vitriol, as two or three grains to an ounce of water, applied to ulcers of the mouth, or to chancres on the glans p.e.n.i.s, more powerfully induces them to heal than any other material.

Where the lungs or urethra are inflamed to a considerable degree, and the absorption is so great, that the mucus is already too thick, and adheres to the membrane from its viscidity, opiates and bitter vegetable and austere acids are improper; and mucilaginous diluents should be used in their stead with venesection and torpentia.

III. 1. Absorption from the cellular membrane, and from all the other cavities of the body, is too slowly performed in some const.i.tutions; hence the bloated pale complexion; and when this occurs in its greatest degree, it becomes an universal dropsy. These habits are liable to intermittent fevers, hysteric paroxysms, cold extremities, indigestion, and all the symptoms of debility.

The absorbent system is more subject to torpor or quiescence than the secerning system, both from the coldness of the fluids which are applied to it, as the moisture of the atmosphere, and from the coldness of the fluids which we drink; and also from its being stimulated only by intervals, as when we take our food; whereas the secerning system is perpetually excited into action by the warm circulating blood; as explained in Sect. x.x.xII.

2. The Peruvian bark, camomile flowers, and other bitter drugs, by stimulating this cellular branch of the absorbent system prevents it from becoming quiescent; hence the cold paroxysms of those agues, which arise from the torpor of the cellular lymphatics, are prevented, and the hot fits in consequence. The patient thence preserves his natural heat, regains his healthy colour, and his accustomed strength.

Where the cold paroxysm of an ague originates in the absorbents of the liver, spleen, or other internal viscus, the addition of steel to vegetable bitters, and especially after the use of one dose of calomel, much advances the cure.

And where it originates in any part of the secerning system, as is probably the case in some kinds of agues, the addition of opium in the dose of a grain and half, given about an hour before the access of the paroxysm, or mixed with chalybeate and bitter medicines, ensures the cure. Or the same may be effected by wine given instead of opium before the paroxysm, so as nearly to intoxicate.

These three kinds of agues are thus distinguished; the first is not attended with any tumid or indurated viscus, which the people call an ague cake, and which is evident to the touch. The second is accompanied with a tumid viscus; and the last has generally, I believe, the quartan type, and is attended with some degree of arterial debility.

3. This cla.s.s of absorbent medicines are said to decrease irritability.

After any part of our system has been torpid or quiescent, by whatever cause that was produced, it becomes afterwards capable of being excited into greater motion by small stimuli; hence the hot fit of fever succeeds the cold one. As these medicines prevent torpor or quiescence of parts of the system, as cold hands or feet, which perpetually happen to weak const.i.tutions, the subsequent increase of irritability of these parts is likewise prevented.

4. These absorbent medicines, including both the bitters, and metallic salts, and opiates, are of great use in the dropsy by their promoting universal absorption; but here evacuations are likewise to be produced, as will be treated of in the Invertentia.

5. The matter in ulcers is thickened, and thence rendered less corrosive, the saline part of it being reabsorbed by the use of bitter medicines; hence the bark is used with advantage in the cure of ulcers.

6. Bitter medicines strengthen digestion by promoting the absorption of chyle; hence the introduction of hop into the potation used at our meals, which as a medicine may be taken advantageously, but, like other unnecessary stimuli, must be injurious as an article of our daily diet.

The hop may perhaps in some degree contribute to the production of gravel in the kidnies, as our intemperate wine-drinkers are more subject to the gout, and ale-drinkers to the gravel; in the formation of both which diseases, there can be no doubt, but that the alcohol is the princ.i.p.al, if not the only agent.

7. Vomits greatly increase the absorption from the cellular membrane, as squill, and foxglove. The squill should be given in the dose of a grain of the dried root every hour, till it operates upwards and downwards. Four ounces of the fresh leaves of the foxglove should be boiled from two pounds of water to one, and half an ounce of the decoction taken every two hours for four or more doses. This medicine by stimulating into inverted action the absorbents of the stomach, increases the direct action of the cellular lymphatics.

Another more convenient way of ascertaining the dose of foxglove is by making a saturated tincture of it in proof spirit; which has the twofold advantage of being invariable in its original strength, and of keeping a long time as a shop-medicine without losing any of its virtue. Put two ounces of the leaves of purple foxglove, digitalis purpurea, nicely dried, and coa.r.s.ely powdered, into a mixture of four ounces of rectified spirit of wine and four ounces of water; let the mixture stand by the fire-side twenty-four hours frequently shaking the bottle, and thus making a saturated tincture of digitalis; which must be poured from the sediment or pa.s.sed through filtering paper.

As the size of a drop is greater or less according to the size of the rim of the phial from which it is dropped, a part of this saturated tincture is then directed to be put into a two-ounce phial, for the purpose of ascertaining the size of the drop. Thirty drops of this tincture is directed to be put into an ounce of mint-water for a draught to be taken twice or thrice a day, till it reduces the anasarca of the limbs, or removes the difficulty of breathing in hydrothorax, or till it induces sickness. And if these do not occur in two or three days, the dose must be gradually increased to forty or sixty drops, or further.

From the great stimulus of this medicine the stomach is rendered torpid with consequent sickness, which continues many hours and even days, owing to the great exhaustion of its sensorial power of irritation; and the action of the heart and arteries becomes feeble from the deficient excitement of the sensorial power of a.s.sociation; and lastly, the absorbents of the cellular membrane act more violently in consequence of the acc.u.mulation of the sensorial power of a.s.sociation in the torpid heart and arteries, as explained in Suppl. I. 12.

A circ.u.mstance curiously similar to this occurs to some people on smoking tobacco for a short time, who have not been accustomed to it. A degree of sickness is presently induced, and the pulsations of the heart and arteries become feeble for a short time, as in the approach to fainting, owing to the direct sympathy between these and the stomach, that is from defect of the excitement of the power of a.s.sociation. Then there succeeds a tingling, and heat, and sometimes sweat, owing to the increased action of the capillaries, or perspirative and mucous glands; which is occasioned by the acc.u.mulation of the sensorial power of a.s.sociation by the weaker action of the heart and arteries, which now increases the action of the capillaries.

8. Another method of increasing absorption from the cellular membrane is by warm air, or by warm steam. If the swelled legs of a dropsical patient are inclosed in a box, the air of which is made warm by a lamp or two, copious sweats are soon produced by the increased action of the capillary glands, which are seen to stand on the skin, as it cannot readily exhale in so small a quant.i.ty of air, which is only changed so fast as may be necessary to permit the lamps to burn. At the same time the lymphatics of the cellular membrane are stimulated by the heat into greater action, as appears by the speedy reduction of the tumid legs.

It would be well worth trying an experiment upon a person labouring under a general anasarca by putting him into a room filled with air heated to 120 or 130 degrees, which would probably excite a great general diaph.o.r.esis, and a general cellular absorption both from the lungs and every other part.

And that air of so great heat may be borne for many minutes without great inconvenience was shewn by the experiments made in heated rooms by Dr.

Fordyce and others. Philos. Trans.

Another experiment of using warmth in anasarca, or in other diseases, might be by immersing the patient in warm air, or in warm steam, received into an oil-skin bag, or bathing-tub of tin, so managed, that the current of warm air or steam should pa.s.s round and cover the whole of the body except the head, which might not be exposed to it; and thus the absorbents of the lungs might be induced to act more powerfully by sympathy with the skin, and not by the stimulus of heat. See Uses of Warm Bath, Art. II. 2. 2. 1.

IV. 1. Venous absorption. Cellary, water-cresses, cabbages, and many other vegetables of the Cla.s.s Tetradynamia, do not increase the heat of the body (except those whose acrimony approaches to corrosion), and hence they seem alone, or princ.i.p.ally, to act on the venous system; the extremities of which we have shewn are absorbents of the red blood, after it has pa.s.sed the capillaries and glands.

2. In the sea-scurvy and petechial fever the veins do not perfectly perform this office of absorption; and hence the vibices are occasioned by blood stagnating at their extremities, or extravasated into the cellular membrane. And this cla.s.s of vegetables, stimulating the veins to perform their natural absorption, without increasing the energy of the arterial action, prevents future petechiae, and may a.s.sist the absorption of the blood already stagnated, as soon as its chemical change renders it proper for that operation.

3. The fluids, which are extravasated, and received into the cells of the cellular membrane, seem to continue there for many days, so as to undergo some chemical change, and are then taken up again by the mouths of the cellular absorbents. But the new vessels produced in inflamed parts, as they communicate with the veins, are probably absorbed again by the veins along with the blood which they contain in their cavities. Hence the blood, which is extravasated in bruises or vibices, is gradually many days in disappearing; but after due evacuations the inflamed vessels on the white of the eye, if any stimulant lotion is applied, totally disappear in a few hours.

Amongst absorbents affecting the veins we should therefore add the external application of stimulant materials; as of vinegar, which makes the lips pale on touching them. Friction, and electricity.

4. Haemorrhages are of two kinds, either arterial, which are attended with inflammation; or venous, from a deficiency in the absorbent power of this set of vessels. In the former case the torpentia are efficacious; in the latter steel, opium, alum, and all the tribe of sorbentia, are used with success.

5. Sydenham recommends vegetables of the cla.s.s Tetradynamia in rheumatic pains left after the cure of intermittents. These pains are perhaps similar to those of the sea-scurvy, and seem to arise from want of absorption in the affected part, and hence are relieved by the same medicines.

V. 1. Intestinal absorption. Some astringent vegetables, as rhubarb, may be given in such doses as to prove cathartic; and, after a part of it is evacuated from the body, the remaining part augments the absorption of the intestines; and acts, as if a similar dose had been exhibited after the operation of any other purgative. Hence 4 grains of rhubarb strengthen the bowels, 30 grains first empty them.

2. The earthy salts, as alum, increase the intestinal absorption, and hence induce constipation in their usual dose; alum is said sometimes to cure intermittents, perhaps when their seat is in the intestines, when other remedies have failed. It is useful in the diabaetes by exciting the absorbents of the bladder into their natural action; and combined with resin is esteemed in the fluor albus, and in gleets. Lime-stone or chalk, and probably gypsum, possess effects in some degree similar, and increase the absorption of the intestines; and thus in certain doses restrain some diarrhoeas, but in greater doses alum I suppose will act as a cathartic.

Five or ten grains produce constipation, 20 or 30 grains are either emetic or cathartic.

3. Earth of alum, tobacco-pipe clay, marl, Armenian bole, lime, crab's eyes or claws, and calcined hartshorn, or bone ashes, restrain fluxes; either mechanically by supplying something like mucilage, or oil, or rollers to abate the friction of the aliment over inflamed membranes; or by increasing their absorption. The two last consist of calcareous earth united to phosphoric acid, and the Armenian bole and marl may contain iron. By the consent between the intestines and the skin 20 grains of Armenian bole given at going into bed to hectic patients will frequently check their tendency to sweat as well as to purge, and the more certainly if joined with one grain of opium.

VI. 1. Absorption from the liver, stomach, and other viscera. When inflammations of the liver are subdued to a certain degree by venesection, with calomel and other gentle purges, so that the arterial energy becomes weakened, four or eight grains of iron-filings, or of salt of steel, with the Peruvian bark, have wonderful effect in curing the cough, and restoring the liver to its usual size and sanity; which it seems to effect by increasing the absorption of this viscus. The same I suppose happens in respect to the tumours of other viscera, as of the spleen, or pancreas, some of which are frequently enlarged in agues.

2. Haemorrhages from the nose, r.e.c.t.u.m, kidnies, uterus, and other parts, are frequently attendant on diseased livers; the blood being impeded in the vena portarum from the decreased power of absorption, and in consequence of the increased size of this viscus. These haemorrhages after venesection, and a mercurial cathartic, are most certainly restrained by steel alone, or joined with an opiate; which increase the absorption, and diminish the size of the liver.

Chalybeates may also restrain these haemorrhages by their promoting venous absorption, though they exert their princ.i.p.al effect upon the liver. Hence also opiates, and bitters, and vitriolic acid, are advantageously used along with them. It must be added that some haemorrhages recur by periods like the paroxysms of intermittent fevers, and are thence cured by the same treatment.

3. The jaundice is frequently caused by the insipidity of the bile, which does not stimulate the gall-bladder and bile-ducts into their due action; hence it stagnates in the gall-bladder, and produces a kind of crystallization, which is too large to pa.s.s into the intestines, blocks up the bile-duct, and occasions a long and painful disease. A paralysis of the bile duct produces a similar jaundice, but without pain.

4. Worms in sheep called flukes are owing to the dilute state of the bile; hence they originate in the intestines, and thence migrate into the biliary ducts, and corroding the liver produce ulcers, cough, and hectic fever, called the rot. In human bodies it is probable the inert state of the bile is one cause of the production of worms; which insipid state of the bile is owing to deficient absorption of the thinner parts of it; hence the pale and bloated complexion, and swelled upper lip, of wormy children, is owing to the concomitant deficiency of absorption from the cellular membrane.

Salt of steel, or the rust of it, or filings of it, with bitters, increase the acrimony of the bile by promoting the absorption of its aqueous part; and hence destroy worms, as well as by their immediate action on the intestines, or on the worms themselves. The cure is facilitated by premising a purge with calomel. See Cla.s.s I. 2. 3. 9.

5. The chlorosis is another disease owing to the deficient action of the absorbents of the liver, and perhaps in some degree also to that of the secretory vessels, or glands, which compose that viscus. Of this the want of the catameniae, which is generally supposed to be a cause, is only a symptom or consequence. In this complaint the bile is deficient perhaps in quant.i.ty, but certainly in acrimony, the thinner parts not being absorbed from it. Now as the bile is probably of great consequence in the process of making the blood; it is on this account that the blood is so dest.i.tute of red globules; which is evinced by the great paleness of these patients. As this serous blood must exert less stimulus on the heart, and arteries, the pulse in consequence becomes quick as well as weak, as explained in Sect.

XII. 1. 4.

The quickness of the pulse is frequently so great and permanent, that when attended by an accidental cough, the disease may be mistaken for hectic fever; but is cured by chalybeates, and bitters exhibited twice a day; with half a grain of opium, and a grain of aloe every night; and the expected catamenia appears in consequence of a restoration of the due quant.i.ty of red blood. This and the two former articles approach to the disease termed paralysis of the liver. Sect. x.x.x. 1. 4.

6. It seems paradoxical, that the same treatment with chalybeates, bitters, and opiates, which produces menstruation in chlorotic patients, should repress the too great or permanent menstruation, which occurs in weak const.i.tutions at the time of life when it should cease. This complaint is an haemorrhage owing to the debility of the absorbent power of the veins, and belongs to the paragraph on venous absorption above described, and is thence curable by chalybeates, alum, bitters, and particularly by the exhibition of a grain of opium every night with five grains of rhubarb.

7. Metallic salts supply us with very powerful remedies for promoting absorption in dropsical cases; which frequently are caused by enlargement of the liver. First, as they may be given in such quant.i.ties as to prove strongly cathartic, of which more will be said in the article on invertentia; and then, when their purgative quality ceases, like the effect of rhubarb, their absorbent quality continues to act. The salts of mercury, silver, copper, iron, zinc, antimony, have all been used in the dropsy; either singly for the former purpose, or united with bitters for the latter, and occasionally with moderate but repeated opiates.

8. From a quarter of a grain to half a grain of blue vitriol given every four or six hours, is said to be very efficacious in obstinate intermittents; which also frequently arise from an enlarged viscus, as the liver or spleen, and are thence owing to the deficient absorption of the lymphatics of that viscus. A quarter of a grain of white a.r.s.enic, as I was informed by a surgeon of the army, cures a quartan ague with great certainty, if it be given an hour before the expected fit. This dose he said was for a robust man, perhaps one eighth of a grain might be given and repeated with greater safety and equal efficacy.

Dr. Fowler has given many successful cases in his treatise on this subject.

He prepares it by boiling sixty-four grains of white a.r.s.enic in a Florence flask along with as much pure vegetable fixed alcali in a pint of distilled water, till it is dissolved, and then adding to it as much distilled water as will make the whole exactly sixteen ounces. Hence there are four grains of a.r.s.enic in every ounce of the solution. This should be put into a phial of such a size of the edge of its aperture, that sixty drops may weigh one dram, which will contain half a grain of a.r.s.enic. To children from two years old to four he gives from two to five drops three or four times a day. From five years old to seven, he directs seven or eight drops. From eight years old to twelve, he directs from seven to ten drops. From thirteen years old to eighteen he directs from ten to twelve drops. From eighteen upwards, twelve drops. In so powerful a medicine it is always prudent to begin with smaller doses, and gradually to increase them.

A saturated solution of a.r.s.enic in water is preferable I think to the above operose preparation of it; as no error can happen in weighing the ingredients, and it more certainly therefore possesses an uniform strength.

Put much more white a.r.s.enic reduced to powder into a given quant.i.ty of distilled water, than can be dissolved in it. Boil it for half an hour in a Florence flask, or in a tin sauce-pan; let it stand to subside, and filter it through paper. My friend Mr. Greene, a surgeon at Brewood in Staffordshire, a.s.sured me, that he had cured in one season agues without number with this saturated solution; that he found ten drops from a two-ounce phial given thrice a day was a full dose for a grown person, but that he generally began with five.

9. The manner, in which a.r.s.enic acts in curing intermittent fevers, cannot be by its general stimulus, because no intoxication or heat follows the use of it; nor by its peculiar stimulus on any part of the secreting system, since it is not in small doses succeeded by any increased evacuation, or heat, and must therefore exert its power, like other articles of the sorbentia, on the absorbent system. In what manner it destroys life so suddenly is difficult to understand, as it does not intoxicate like many vegetable poisons, nor produce fevers like contagious matter. When applied externally it seems chemically to destroy the part like other caustics.