The Action of Medicines in the System / Or, on the mode in which therapeutic agents introduced into the stomach produce their peculiar effects on the animal economy

FOOTNOTES:

[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."

[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.

[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.

[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.

[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.

[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.

[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 is divisible to any thing like this extent.

[14] Sydenham's Works, translated from the Latin by Dr. Swan. 5th edition, 1769, p. 1.

[15] Preface to the same, p. 22.

[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.

[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 be partly propagated by means of the nervous system. Op. cit. p. 127.

[20] Vide Paper in Medical Gazette, June 18th, 1841.

[21] Todd and Bowman's Physiology, vol. ii. p. 280.

[22] Vide Pereira's Materia Medica, vol. i. pp. 101, 106.

[23] Such is the case in health, when the muscular pressure of the intestine must exceed the pressure on the vascular system on the other side. This latter pressure, when increased, tends to stop or to reverse the inward current. Thus plethora and fever, diseased conditions, counteract absorption by causing pressure on the coats of these capillary vessels. Bleeding,—a drain of fluid caused by an increased secretion,—or such agents as Tartar Emetic and Ipecacuanha,—diminish this pressure by weakening the force of the heart, and thus favour natural absorption.

[24] It is stated by Dr. Carpenter, that if a ligature be applied below the pylorus of an animal, and Sulphate of Magnesia then introduced into the stomach, purging is produced. This could only be by the absorption of the salt, and its subsequent action from within on the mucous membrane of the bowel below the ligature. This experiment is unauthenticated, but if verified would certainly be most conclusive in favour of the view adopted above.

[25] Hydrochloric acid would probably precipitate medicinal solutions containing silver, and thus render this substance inert when given internally. Another therapeutic argument against this, as the acid of the gastric secretion, may be drawn from the fact that the action of calomel is very different from that of bichloride of mercury,—whereas this acid would convert the former into the latter.

[26] Liebig (Animal Chemistry, Part I. p. 76) states that the Bile contains Carbonate of Soda. The assertion that the Pancreatic juice is alkaline must be rested mainly on the authority of M. Bernard.

[27] Occasionally, as in certain cases of Pyrosis, slight vomiting may take place without any straining effort of this kind, but apparently from the contraction of the stomach alone.

[28] Pereira's Materia Medica, 2d edit., vol. ii. pp. 1496, 1507, and elsewhere.

[29] Irritant Cathartics, like irritant emetics, may sometimes affect remote parts on the principle of counter-irritation. Some explain in this way the use of purgatives in disorders of the brain, but there are other reasons which serve to account for this still more satisfactorily. (Vide Chap. IV., Art. Purgatives.)

[30] The process of cure by counter-irritation may be ascribed to the secondary action of some medicines. Such an operation may take place at a distance from the part affected; but it is attributable to a peculiar affection of the nervous system, and has no necessary connexion with the primary or proper action of a medicine. Vide p. 67.

[31] The details of this arrangement are founded solely upon the therapeutic operation of medicines, as used to cure diseases, and not in any way upon their physiological action upon a healthy man. Much unnecessary confusion, in works on Materia Medica, has arisen from these two different matters being taken into account at the same time. Food is the only restoration of wanting material needful to a healthy man; neither is there in such a case any need or opportunity for the counteraction of morbid agencies.

[32] Animal Chemistry, p. 20.

[33] Possibly some parts of the bile, besides the colouring matter, are truly excrementitious. But part of it is needful in the animal economy, as has been proved by experiment. M. Schwann found that when the contents of the bile-duct in dogs were caused to discharge themselves externally through a fistulous opening in the wall of the abdomen, the animals quickly wasted away and died. In some cases of jaundice, the constituents of the bile appear to be vicariously excreted by the kidneys; and perhaps the great depression produced by that disorder maybe partly accounted for by the impossibility of the re-absorption into the blood of these substances, naturally formed by the liver. Having passed into the urine, there is no provision to enable them to return.

[34] He states that one equivalent of binoxalate of ammonia and four of water contain together the same elements as an atom of Taurine. (Vide Simon's Animal Chemistry, vol. i. p. 47. Syd. Society.)

[35] A deposit of Oxalate of Lime occurs sometimes. It is seen in minute octahedra; but is rarely in sufficient quantity to be distinguished by chemical tests. It does not come within the influence of Solvent medicines.

[36] Some suppose that this acid occurs in healthy urine is a free state. It is more commonly thought to exist as Urate of Ammonia. Lehmann states that it is found as Urate of Soda. Others imagine that it is held in solution by means of Phosphate of Soda.

[37] This acid is ascribed by some to Urate of Ammonia, which is to a small extent soluble in water. Others consider that it is due both to this and to Phosphoric acid, which is the opinion of Dr. Prout and Dr. G. Bird. Others attribute it to Lactic acid, which is stated by Berzelius, Lehmann, and Simon, to exist in healthy urine. Some consider the acid to consist in a Super-phosphate of Soda. Liebig supposes that it is due to Uric acid, held in solution by the common Phosphate of Soda. He also considers Hippuric acid to be an invariable ingredient in healthy human urine.

[38] According to Simon it is 1.0125; Becquerel makes it 1.017; Dr. Prout and Dr. Golding Bird, 1.020; Berzelius rates it still higher.

[39] "The state or condition of formation or decomposition of a body, the state of change of place or motion in which its particles are, exerts an influence on the particles of many other compounds, if in contact with them. The latter are brought into the same state; their elements are separated and newly arranged in a similar way, and acquire the power of entering into combination, a power which they did not, under similar circumstances, previously possess."—Liebig's Animal Chemistry, vol. i. p. 194.

[40] Dr. Mead, in 1751, recommended the employment in Scrofula of burnt sponge, and a pill containing "sublimed Mercury" and precipitated Sulphuret of Antimony. Plummer's pill is often prescribed in these cases at the present day.

[41] Among these, Dock, Sorrel, Wood-sorrel, and Stonecrop, may be mentioned. Such herbs have been long employed, and recommended by authority. Dr. Mead, in 1751, recommended Scurvy-grass, Lettuce, and Brooklime. He also made particular mention of the Herba Britannica, which seems to have been the great Dock, Rumex hydrolapathum. The same physician appears to have anticipated some of the modern applications of Lemon juice. He employed it in liver-diseases generally, among which he included a number of dyspeptic and gouty disorders. He gave it in six-drachm doses; and says that he employed also in similar cases saponaceous medicines, and rhubarb. These remedies, apparently heterogeneous, were recognised then, as now, to be useful in the same cases. For we have just seen that Lemon-juice, Alkalies, Cholagogues, and Tonics, are all more or less applicable in diseases of the Arthritic group.

[42] I have just said that Neurotic medicines influence those functions which are attributed to the nervous system. Now there can be no reasonable doubt that they actually influence the nerves. But it is worth while to notice here the curious fact that the same agents have been found to paralyze the irritable or contractile tissues of certain vegetables. Professor Marcet of Geneva first noticed that the vapours of Chloroform and Ether affected the leaf of the sensitive plant so as to prevent it from contracting at the touch, but without at the same time perceptibly injuring its structure. I have produced the same effect on a species of Acacia, which naturally closes its leaves at the approach of night. The leaf experimented on remained open, while the others closed. After a certain time it recovered. Solutions of Morphia, Conia, and other sedatives, have been found to produce the same result. Now the existence in plants of nervous tissues is not usually admitted. How then are we to explain the analogous action of these paralyzing Neurotics on animals and vegetables? Possibly they may be capable of acting directly on contractile or irritable tissues in both cases, without necessarily influencing the nerves in order to produce paralysis.

[43] Turner's Chemistry, 7th edit., p. 995.

[44] I do not here mean to imply that the products of the actions of all glands are destined for excretion. It is probable that the bile and some other secretions are partly re-absorbed into the blood. But we are now concerned only with the function of glands as emunctories.

[45] No lists of the Eliminative orders will be given; for as only a general outline of the mode of action of these medicines is intended, a detailed enumeration of the remedies comprised in each order would be a needless appropriation of space.

[46] It has been asserted by Dr. Murray that it is impossible for Mercury to pass off in the urine, on account of the Phosphoric acid contained in that secretion, which would precipitate the metal. But Phosphoric acid is also contained in the blood; and Mercury has been discovered in the urine.

[47] Reference is made at the end of each article to those parts of the Essay in which the remedy has been mentioned before.

[48] See Pereira's "Materia Medica," vol. i. p. 204.

[49] See account of the mode of preparation, by the Author, in the second edition of Dr. Royle's "Manual of Materia Medica."

Transcriber's Note

The apothecaries' symbol for the dram (?) is used in this book. "?j" is 1 dram, and "?ss" is ½ dram. The apothecaries' dram is 3.8879346 grams.

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