Copy 1, Volume 1

The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good].

  • John Mason Good
Date:
1834
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Licence: Public Domain Mark

Credit: The study of medicine. Improved from the author's manuscripts, and by reference to the latest advances in physiology, pathology, and practice / [John Mason Good]. Source: Wellcome Collection.

    153/784 page 99
    jl . cee 26L. 15] 7 DIGESTIVE FUNCTION. [orp. 1. 99 the veins would, by mixing with the venous blood, have the effect Gry. IV. of quenching thirst in the same manner as drink taken in the ordinary way. ‘his conjecture is now ascertained to be a fact. Dupuy- By injecting water, milk, whey, and other fluids into the veins, tren’s ex- Baron Dupuytren has frequently appeased the thirst of animals Perments. subjected to experiment, and long exposed toa burning sun. ' By varying such experiments with liquids known to be agreeable or disagreeable to dogs, he found, that the animals derived from these liquids, so employed, the same sensation of taste as if they had been given by the mouth. In fact, when milk was thrown into the jugular vein, the dogs made a lapping motion, just as if they were really taking the milk up with their tongues. Some analogous experiments were made by Professor Orfila. In Orfila’s ex- his valuable researches on Toxicology, he had frequent. occasion to periments. tie the cesophagus in dogs, in order to hinder the expulsion of poisons which they had swallowed. For the purpose of appeasing their thirst, excited by the fever resulting from the extensive wound in their necks, he injected water into their jugular veins. This method of quenching thirst, the only one practicable while the cesophagus was tied, was performed in a great number of in- stances, and always gave immediate relief. The blood of animals which had been long in a thirsting state, was also submitted to distillation, and the diminution of its aqueous part was always found to be in proportion to the length of their. abstinence from drink.* The principal fact, interfering with the foregoing theory, is that of the frequently sudden production of thirst, without any previous abstinence from drink, sufficient to justify the suspicion of the watery part of the blood having been in any way particularly lessened. But, although much obscurity prevails concerning the efficient cause of hunger and thirst, their final cause is sufficiently obvious: they are the means, by which we are warned of the necessity of supplying the system with materials requisite for its existence. -They belong to that class of actions which are termed appetites ; where an effect, which is a compound of a physical and a mental operation, is connected with an evidently useful purpose in the animal economy.+ ] The common modes of quenching these agonising sensations are These well known to be eating and drinking: yet, whem these cannot be sensations indulged in, other modes may answer as a substitute. Thus, »°w She, violent pressure against the coats of the stomach, whether ex- 2°™* ternally or internally, is well known to take off the gnawing sensa- tion of hunger ; and stimulating the fauces, to take off the burning faintness of thirst. It is on this last account that chewing a mouth- ful of hay, alone, or merely moistened with water, proves so refreshing to a tired horse, and is found so serviceable when we dare not allow him, in the midst of a long stage, to slake his thirst in the natural way. Savages and savage beasts are equally sensible of the benefit of pressure in the case of hunger, and resort to it upon all occasions where they have no opportunity of taking off Pressure the pain in the usual way. The manis, or pangolin, that swallows employed its food whole, will swallow stones, coals, or any other substance if deaden hunger by * See Dicts des Sciences Méd , tom. li. p. 469. savage t+ See Bostock’s Physiology, vol. ii. p. 531. beasts,
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