Tannic acid = C18H6O10+ 2 aq.Gallic acid = C7HO3+ 2 aq.
Tannic acid = C18H6O10+ 2 aq.
Gallic acid = C7HO3+ 2 aq.
Three equivalents of anhydrous Tannic acid amount to six of Gallic acid and one of grape-sugar.
3(C18H6O10) = 6(C7HO3) + C12H12O12.
3(C18H6O10) = 6(C7HO3) + C12H12O12.
So that it is very probable that when Gallic acid is taken into the blood, it acts as an Astringent by co-operating or uniting with the elements of grape-sugar in that fluid. But when Tannic acid is received into the organism, and has done its work there, it is finally decomposed, Gallic acid passing out into the secretions, and the sugar being retained in the body for combustion into carbonic acid and water. (P. 116.)
The principal vegetable substances that are employed as Astringents are said to contain Tannic acid in the following proportions:—
These numbers are a tolerably fair measure of the astringent power of the substances named. But it must not be supposed that the astringent principle is in all cases strictly identical with Tannic acid, properly so called; for there appear to be various modifications of this substance contained in the different plants, many of which have peculiar chemical characters of their own, but all of which agree in possessing the power of tanning, or combining with animal gelatine, and in the medicinal property of astringency.
Absorption, action of medicines by,61,68,87.
Acids,120.
Aconite,352.
Aconitina, symptoms of action of,353.
Ague, remedies used for,129,207.
Alcohol,339.
Aliments,115.
Alkalies,126.
Aloes, absorption and action of,80,96,289.
Alteratives,35,157,165.
Alum, as an Astringent,263.
Ammonia,334.
Anæmia, treatment of,148,320.
Anthelmintics,97.
Antidotes, action of,92.
Antimony,321.
Arsenic,333.
Astringents,256,358.
Belladonna,240.
Benzoic acid in lithic deposits,156.
Bile, relation of remedies to the,137.
Billing, Dr., on action of medicines,132,163,216.
Bismuth, nitrate of,87,94,97.
Blood, medicinal actions in the,103,106,167.
Borax, actions of,155,232.
Brodie, Sir B., his experiments,63.
Calomel, not a sedative,328.
Cantharides, its uses,67,214,307.
Castor oil,291.
Catechu,358.
Cathartics,95,286.
Chalk, not astringent,264.
Charcoal, said to become absorbed,88.
Chemical theories of medicinal actions,47.
Chlorine, an Antiscrofulic,193.
Chloroform,342.
Cholagogues,295.
Cinchona,129.
Citric acid, its actions,123,202,205.
Cod-liver oil,310.
Colchicum,331.
Conium, its actions,246.
Copaiba, action of,267.
Copper, Sulphate of,93,211,264.
Counter-irritants, action of,67,91.
Creosote, actions of,94,245,265.
Diabetes, treatment of,119,194.
Diaphoretics,298.
Diarrhœa, treatment of,294.
Diet, rules of,118.
Digestion of medicines,68-86,104.
Digitalis,356.
Diuretics,302.
Duncan, Dr., his classification,34.
Dropsy, treatment of,307,355.
Eberle, his arrangement of medicines,39.
Elaterium, its modes of action,85,289.
Eliminatives,268.
Emetics,92,324.
Emmenagogues,102,275.
Endosmosis, passage of medicines by,71.
Epilepsy, remedies used in,211,229,337,345.
Ergot of Rye,233.
Ether,343.
Evacuants, action of,55,269,280.
Expectorants,283.
Fermentations in the blood,180.
Fevers, treatment of,124,185,188,302.
Gallic acid,265,357.
Gold, its use in Syphilis,189.
Gout, treatment of,194,331.
Grape-sugar in the blood,116,198.
Hæmatosin, relation of to Iron,145.
Hæmorrhage, treatment of,263.
Homœopathy, fallacies of,53,184.
Hydrocyanic acid,351.
Hyoscyamus,240.
Hysteria, remedies used in,211,232,337.
Inflammations, treatment of,185,323,325.
Iodide of Potassium,188,191,328.
Iodine,328.
Ipecacuanha, actions of,249,283,295,298.
Iron,145,319.
Jalap, absorption and action of,85,96,289.
Lactic acid in the system,69,116,198.
Laxatives,287.
Lead, actions of,211,254,263.
Lemon-juice, uses of,202,205.
Local access, rule of,98.
Magendie, M., his experiments,63.
Masticatories,281.
Mechanical theories of medicinal actions,43,219.
Mercury,325.
Morphia, modus operandi of,220,347.
Murray, Dr., his classification,36.
Narcotics,234.
Nitric acid, its uses,120,196.
Nitrohydrochloric acid in Oxaluria,196.
Nux vomica,337.
Œsterlen, Prof., on absorption of medicines,88.
Oils, fixed, absorption and action of,84,278,288.
Oils, volatile, their actions,227,267,278.
Opium,346.
Pain, treatment of,342.
Pereira, Dr., on action of medicines,40,131,162,228.
Phosphoric acid, not astringent,262.
Phosphorus, its actions,229,311.
Pitch, used in Lepra,214.
Potash,315.
Purgatives,286.
Quinine,317.
Refrigerants, chemical theory of,123.
Resins, absorption and action of,83,279,288.
Rheumatism, remedies used in,194.
Rhubarb, action of,294.
Salines, absorption and mode of action of,74,188,289,300.
Salt, common, its actions,93,193,210.
Sarsaparilla in Syphilis,190.
Scammony, absorption and action of,85,96,289.
Schultz, classification of,57.
Scrofula, treatment of,191.
Scurvy, remedies used in,205.
Sedatives,242.
Senna, chemical nature and action,279,289.
Sialagogues,281.
Silver, nitrate of, its actions,211,264.
Skin diseases, treatment of,213.
Special Sedatives,249.
Special Stimulants,233.
Squill, its doubtful action,253.
Starch, digestion of,82,116,197.
Stimulants,226.
Stramonium,240.
Strychnia,337.
Sulphur, in skin diseases,215,301.
Sulphuric acid,313.
Syphilis, treatment of,188.
Tannic acid,356.
Tartar emetic,321.
Tea, a Sedative,248.
Thomson, Dr. A. T., on action of medicines,39.
Tonics,129.
Turpentine, its modes of action,229,267,305.
Urinary deposits, treatment of,149,307.
Water, its elimination,154,300,307.
Young, Dr., his classification,32.
Zinc, sulphate of, its actions,93,211,264.
[1]"In reasoning as to the probable effects of particular remedies on the human body, the conditions and circumstances of the latter are so various in different cases, and the number of concomitants which have to be considered in addition to the more obvious facts and symptoms, is so great that the utmost exertion of human sagacity, founded upon the largest induction of particulars which any one mind is capable of embracing and retaining, can do no more than approximate to that real evidence of which the case seems by its proper nature to be susceptible."—Glassford's Principles of Evidence.
[1]"In reasoning as to the probable effects of particular remedies on the human body, the conditions and circumstances of the latter are so various in different cases, and the number of concomitants which have to be considered in addition to the more obvious facts and symptoms, is so great that the utmost exertion of human sagacity, founded upon the largest induction of particulars which any one mind is capable of embracing and retaining, can do no more than approximate to that real evidence of which the case seems by its proper nature to be susceptible."—Glassford's Principles of Evidence.
[2]Dr. A. Pitcairn, in 1704, concluded one of his works by saying, "Thus have I succeeded in solving the noble problem, viz., to find a remedy for a given disease.Jamque opus exegi."
[2]Dr. A. Pitcairn, in 1704, concluded one of his works by saying, "Thus have I succeeded in solving the noble problem, viz., to find a remedy for a given disease.Jamque opus exegi."
[3]"In the mean time it may suffice for the physician to know the effects of a medicine when applied to the body, though he knows not the particular manner whereby it acts."—Van Sweiten's Commentaries on Boerhaave, vol. i. p. 394.
[3]"In the mean time it may suffice for the physician to know the effects of a medicine when applied to the body, though he knows not the particular manner whereby it acts."—Van Sweiten's Commentaries on Boerhaave, vol. i. p. 394.
[4]"Every branch of study which can at all claim the character of a science requires two things: 1. A correct ascertainment of the data from which we are to reason; and 2. Correctness in the process of deducing conclusions from them."—Whateley's Elements of Logic.
[4]"Every branch of study which can at all claim the character of a science requires two things: 1. A correct ascertainment of the data from which we are to reason; and 2. Correctness in the process of deducing conclusions from them."—Whateley's Elements of Logic.
[5]There is no doubt that the small veins which ramify outside the coats of the stomach and intestines are capable of taking up any matters in a state of proper solution, even fats when dissolved in alkali. But are medicines ever taken up by the lacteal absorbents? Probably seldom or never; for it seems that these vessels are only engaged after a full meal, and subsequent to the regular formation of chyle. They do not exist in the coat of the stomach, but commence in the small intestine at some distance from the pylorus.
[5]There is no doubt that the small veins which ramify outside the coats of the stomach and intestines are capable of taking up any matters in a state of proper solution, even fats when dissolved in alkali. But are medicines ever taken up by the lacteal absorbents? Probably seldom or never; for it seems that these vessels are only engaged after a full meal, and subsequent to the regular formation of chyle. They do not exist in the coat of the stomach, but commence in the small intestine at some distance from the pylorus.
[6]It may be of some use if I adduce here a characteristic example of each of the great groups of medicines to which I have alluded above:Class I.Hæmatics.Div. 1. Restoratives. Iron, in Anæmia.Div. 2. Catalytics. Mercury, in Syphilis.Class II.Neurotics.Div. 1. Stimulants. Ammonia.Div. 2. Narcotics. Opium.Div. 3. Sedatives. Hydrocyanic Acid.Class III.Astringents.Tannic Acid.Class IV.Eliminatives.Cantharides, and Croton Oil.
[6]It may be of some use if I adduce here a characteristic example of each of the great groups of medicines to which I have alluded above:
Class I.Hæmatics.
Div. 1. Restoratives. Iron, in Anæmia.
Div. 2. Catalytics. Mercury, in Syphilis.
Class II.Neurotics.
Div. 1. Stimulants. Ammonia.
Div. 2. Narcotics. Opium.
Div. 3. Sedatives. Hydrocyanic Acid.
Class III.Astringents.Tannic Acid.
Class IV.Eliminatives.Cantharides, and Croton Oil.
[7]The whimsical "doctrine of signatures" which prevailed in the middle ages, and had its origin from very remote times, serves at least to show that the local tendencies of medicines have always been more or less recognised. So slight an experience is sufficient to demonstrate their existence, that it could indeed hardly be otherwise. It was oddly supposed that every natural substance bore evidence in its outward form or physical peculiarities of the part of the system over which it exerted a curative power.
[7]The whimsical "doctrine of signatures" which prevailed in the middle ages, and had its origin from very remote times, serves at least to show that the local tendencies of medicines have always been more or less recognised. So slight an experience is sufficient to demonstrate their existence, that it could indeed hardly be otherwise. It was oddly supposed that every natural substance bore evidence in its outward form or physical peculiarities of the part of the system over which it exerted a curative power.
[8]"He was one of the first who, leaving the old conjectural method of physical writers, struck into a new and more solid way of reasoning, grounded upon observations and mathematical principles."—Preface to Dr. Pitcairn's Works: 1715.
[8]"He was one of the first who, leaving the old conjectural method of physical writers, struck into a new and more solid way of reasoning, grounded upon observations and mathematical principles."—Preface to Dr. Pitcairn's Works: 1715.
[9]"A Treatise of Diseases in General, wherein the true causes, natures, and essences of all the principal diseases incident to the human body, are mechanically accounted for and explained, and their respective intentions of cure assigned upon the same principles," vol. ii. p. 813, 820.
[9]"A Treatise of Diseases in General, wherein the true causes, natures, and essences of all the principal diseases incident to the human body, are mechanically accounted for and explained, and their respective intentions of cure assigned upon the same principles," vol. ii. p. 813, 820.
[10]"Medical Precepts and Cautions," page 294.
[10]"Medical Precepts and Cautions," page 294.
[11]"If there be any bodies—suppose gold and silver—out of which all these principles cannot be drawn, let not the artist think that it is because they are not therein contained. No! it is because that God has so firmly united them against the possibility of our separation."—P. 809.
[11]"If there be any bodies—suppose gold and silver—out of which all these principles cannot be drawn, let not the artist think that it is because they are not therein contained. No! it is because that God has so firmly united them against the possibility of our separation."—P. 809.
[12]Dr. Pitcairn's Works, 1715, p. 219.
[12]Dr. Pitcairn's Works, 1715, p. 219.
[13]I have omitted here to make mention of the doctrine of infinitesimal doses, not only because it is out of my province, but because it is really too unreasonable to be even discussed. When it is said that the decillionth of a grain—the ordinary dose among these practitioners—is expressed by a fraction, the denominator of which is a unit followed by sixty ciphers, this statement will be surely enough for any man who is at all acquainted with figures. I do not conceive it possible that matter isdivisibleto any thing like this extent.
[13]I have omitted here to make mention of the doctrine of infinitesimal doses, not only because it is out of my province, but because it is really too unreasonable to be even discussed. When it is said that the decillionth of a grain—the ordinary dose among these practitioners—is expressed by a fraction, the denominator of which is a unit followed by sixty ciphers, this statement will be surely enough for any man who is at all acquainted with figures. I do not conceive it possible that matter isdivisibleto any thing like this extent.
[14]Sydenham's Works, translated from the Latin by Dr. Swan. 5th edition, 1769, p. 1.
[14]Sydenham's Works, translated from the Latin by Dr. Swan. 5th edition, 1769, p. 1.
[15]Preface to the same, p. 22.
[15]Preface to the same, p. 22.
[16]"First Lines of the Practice of Physic." Fourth edition, 1784. Vol. i. p. 126 et seq.
[16]"First Lines of the Practice of Physic." Fourth edition, 1784. Vol. i. p. 126 et seq.
[17]An exception should be made here of certain animal poisons, such as the venom of serpents, which, though they act on the system when introduced directly into the blood, seems to be rendered innocuous by the action of the stomach, which probably decomposes them.
[17]An exception should be made here of certain animal poisons, such as the venom of serpents, which, though they act on the system when introduced directly into the blood, seems to be rendered innocuous by the action of the stomach, which probably decomposes them.
[18]Physiological Researches, p. 63-67.
[18]Physiological Researches, p. 63-67.
[19]It should be mentioned that Sir Benjamin Brodie, though admitting the force of the above experiments, and deriving from them very similar inferences, yet considers it likely that the action of a medicine or poison may bepartlypropagated by means of the nervous system.Op. cit.p. 127.
[19]It should be mentioned that Sir Benjamin Brodie, though admitting the force of the above experiments, and deriving from them very similar inferences, yet considers it likely that the action of a medicine or poison may bepartlypropagated by means of the nervous system.Op. cit.p. 127.
[20]VidePaper in Medical Gazette, June 18th, 1841.
[20]VidePaper in Medical Gazette, June 18th, 1841.